Chapter 6.3 · Report

Precincts within counties

In 2024, 65.0% of two-party presidential votes in the sample were cast in precincts decided by 20 points or more, against 57.2% in counties decided by that margin.

Author: Vishal Singh
Affiliation: NYU Stern
Published: 30 September 2026

Every estimate of the chapter with its interval and every figure as a table, generated from the chapter's data files. Table n of this report is figure n of the chapter. The same report as Markdown: report.md.

Identification

Title

Precincts within counties

Chapter

6.3 (Part VI, Election results at different scales; Votes, giving and places)

Question

How much do precinct margins vary inside a county, and which counties vary most?

Dek

In 2024, 65.0% of two-party presidential votes in the sample were cast in precincts decided by 20 points or more, against 57.2% in counties decided by that margin.

Grain

places

Status

draft

Published

30 September 2026

Updated

not revised

Data sources

Precinct presidential returns. MIT Election Data and Science Lab, 2024 presidential returns by precinct (Harvard Dataverse), two-party votes per reporting unit; years: 2016, 2020, 2024; weights: none (full counts); statistics weighted by two-party votes
County election returns. Certified 2024 county totals from the repaired county file, used to check each county's precinct rows; years: President 1868-2024 (40 elections); House and Senate 1990-2024; weights: none (full counts)
County demographics panel. County panel: ACS 2024 nonwhite share, rural share and Rural-Urban Continuum Code 2023; years: 2000-2024 (election years, interpolated between census and survey anchors); weights: none (county values; counties weighted by two-party votes in the correlations)

Canonical URL

https://vishalsingh.org/politics/precincts-within-counties

Markdown

https://vishalsingh.org/politics/precincts-within-counties/report.md

BibTeX

@misc{singh2026precinctswithincounties,
  author = {Singh, Vishal},
  title = {Precincts within counties},
  year = {2026},
  url = {https://vishalsingh.org/politics/precincts-within-counties},
  note = {In The Public Mind. Published 30 September 2026.}
}

Principal estimates

The facts the dek and the opening prose cite, in order of appearance. Every fact is in the table of all estimates below.

Estimand	Population	Period	Value	Interval	n	Weights	Source	Fact id
share of votes cast in precincts in the band	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election	65.0%			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns	share_land_precinct
definition	definition used in this chapter	2024 presidential general election	20			none (definition)	Precinct presidential returns	cut_land
share of votes cast in counties in the band	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election	57.2%			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns	share_land_county
sum of Democratic and Republican votes	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election	149.0 million			none (full counts)	Precinct presidential returns	votes_sample
share of votes cast in precincts in the band	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election	18.5%			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns	share_comp_precinct
definition	definition used in this chapter	2024 presidential general election	10			none (definition)	Precinct presidential returns	cut_comp
share of votes cast in counties in the band	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election	23.1%			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns	share_comp_county
mean of county spreads weighted by two-party votes	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	23.3	95% CI 22.5 to 24.1	2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	sd_vw_mean
definition	definition used in this chapter	2024 presidential general election	5			none (definition)	Precinct presidential returns	cut_near
definition	definition used in this chapter	2024 presidential general election	20			none (definition)	Precinct presidential returns	cut_near_units
definition	definition used in this chapter	2024 presidential general election	60%			none (definition)	Precinct presidential returns	land_equiv
definition	definition used in this chapter	2024 presidential general election	55%			none (definition)	Precinct presidential returns	comp_equiv
definition	definition used in this chapter	2024 presidential general election	30			none (definition)	Precinct presidential returns	cut_sd
definition	definition used in this chapter	2024 presidential general election	15			none (definition)	Precinct presidential returns	sd_equiv
two-party margin, Democratic positive	Bucks County, PA	2024 presidential general election	−0.1			none (full counts)	Precinct presidential returns	bucks_margin
count	Bucks County, PA	2024 presidential general election	304			none (full counts)	Precinct presidential returns	bucks_units
vote-weighted standard deviation of precinct margins	Bucks County, PA	2024 presidential general election	14.8		304	none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns	bucks_sd
share of votes cast in precincts decided by under 10 points	Bucks County, PA	2024 presidential general election	50.0%			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns	bucks_comp
margin of the most Democratic precinct	Bucks County, PA	2024 presidential general election	42.0			none (full counts)	Precinct presidential returns	bucks_max_d
margin of the most Republican precinct, as a Republican lead	Bucks County, PA	2024 presidential general election	33.7			none (full counts)	Precinct presidential returns	bucks_max_r
two-party margin, Democratic positive	Centre County, PA	2024 presidential general election	+2.9			none (full counts)	Precinct presidential returns	centre_margin
count	Centre County, PA	2024 presidential general election	87			none (full counts)	Precinct presidential returns	centre_units
vote-weighted standard deviation of precinct margins	Centre County, PA	2024 presidential general election	36.3		87	none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns	centre_sd
share of votes cast in precincts decided by under 10 points	Centre County, PA	2024 presidential general election	5.5%			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns	centre_comp
margin of the most Democratic precinct	Centre County, PA	2024 presidential general election	65.0			none (full counts)	Precinct presidential returns	centre_max_d
margin of the most Republican precinct, as a Republican lead	Centre County, PA	2024 presidential general election	75.2			none (full counts)	Precinct presidential returns	centre_max_r
count	reporting units (precincts) in the analysis sample	2024 presidential general election	175,345			none (full counts)	Precinct presidential returns	n_units
count	counties in the analysis sample	2024 presidential general election	3,043			none (full counts)	Precinct presidential returns	n_counties
count	states in the analysis sample, not counting the District of Columbia	2024 presidential general election	48			none (full counts)	Precinct presidential returns	n_states
count	Louisiana parishes	2024 presidential general election	64			none (full counts)	Precinct presidential returns	n_out_la
ratio of precinct votes to certified votes	Louisiana parishes	2024 presidential general election	51.5%			none (full counts)	Precinct presidential returns	la_share
count	counties outside Louisiana whose precinct rows do not add to the certified total	2024 presidential general election	6			none (full counts)	Precinct presidential returns	n_out_other
count	counties whose precinct rows do not add to the certified total (Louisiana and others)	2024 presidential general election	70			none (full counts)	Precinct presidential returns	n_out_total
share	all counties with returns	2024 presidential general election	2.0%			none (full counts)	County election returns	out_share_cert
share of certified two-party votes cast in Alaska	all counties with returns	2024 presidential general election	0.2%			none (full counts)	County election returns	alaska_share_cert
count	counties in the analysis sample	2024 presidential general election	190			none (full counts)	Precinct presidential returns	n_below_floor
definition	definition used in this chapter	2024 presidential general election	5			none (definition)	Precinct presidential returns	cut_floor_units
count	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	2,853			none (full counts)	Precinct presidential returns	n_counties_disp
definition	definition used in this chapter	2024 presidential general election	2,000			none (definition)	Precinct presidential returns	n_boot

Findings

In 2024, 65.0% of the 149.0 million two-party presidential votes in this chapter's sample were cast in precincts decided by 20 points or more, against 57.2% cast in counties decided by that margin. At the other end, 18.5% of votes were cast in precincts decided by under 10 points, against 23.1% in counties. A precinct here is a reporting unit, the area for which an election office reports its votes, and not a neighborhood.

A county's margin is the average of its precinct margins weighted by their votes. This chapter measures how far the precinct margins vary around that average, and which counties vary most. The standard deviation of precinct margins inside a county, called its spread here, has a mean across counties of 23.3 (95% CI 22.5 to 24.1) points when each county counts in proportion to its votes. Spread is higher in metro counties and in counties that lean Democratic, and it varies widely among counties that finished near a tie, with a margin under 5 points and at least 20 precincts.

A two-party margin is the Democratic vote minus the Republican vote over their sum, in points, and a positive margin is a Democratic lead. A margin of 20 points gives the winner 60% of the two-party vote, and a margin of 10 points gives the winner 55%. The spread is weighted by each precinct's two-party votes and stated in the same points. A county that cast equal numbers of votes in precincts at Democratic +30 and at Republican +30 would have a margin of zero and a spread of 30, which is 15 points of Democratic vote share. Third-party votes are left out.

Two Pennsylvania counties that finished nearly even show what spread measures. Table 1 gives the share of each county's votes by the margin of the precinct where they were cast. Bucks County finished at a margin of −0.1 points, with 304 precincts and a spread of 14.8, and 50.0% of its votes were cast in precincts decided by under 10 points. Its most Democratic precinct had a margin of 42.0 points and its most Republican a Trump lead of 33.7. Centre County finished at +2.9 with 87 precincts and a spread of 36.3, and only 5.5% of its votes were cast in precincts that close. The most Democratic precinct in Centre County had a margin of 65.0 points and the most Republican a Trump lead of 75.2. The Neighborhoods explorer will map these counties and others below the precinct level.

Table 1. Bucks County precincts cluster near an even split, while Centre County precincts form two groups, one on each side

How the gap between precincts and counties changes across scales, from states to blocks, is the subject of Planned, Sorting by geographic scale, 2016 to 2024 (planned), a planned chapter. This chapter asks what the precinct distribution looks like inside each county, which is the information that a county color leaves out. County-level maps supported the argument that Americans sort into like-minded places [1], a claim that others contested [2], and address-level data show that many voters live with almost no exposure to voters of the other party [3]. Precinct returns sit between the two scales.

The sample covers 175,345 reporting units in 3,043 counties in 48 states and the District of Columbia; Alaska and Louisiana are absent.The precinct file from the MIT Election Data and Science Lab reports votes by whatever unit each state or county election office uses, so a precinct here is a reporting unit and differs in size and kind by state. Alaska is left out because its 2024 county codes are election districts. So are the 64 Louisiana parishes, where the precinct rows hold 51.5% of the certified vote, and 6 other counties whose precinct rows do not add to the certified county total. The 70 excluded counties hold 2.0% of certified votes, and Alaska holds a further 0.2%. 190 counties in the sample have too few reporting units for a spread. A county needs at least 5 reporting units to have a spread, which leaves 2,853 counties. The returns are full counts, so shares and spreads carry no sampling error; a statistic across counties, such as a mean or a correlation, carries a 95% interval from resampling counties 2,000 times.

Precincts are more lopsided than the counties that contain them

Table 2 counts the same votes by the margin of the precinct they were cast in, by the margin of the county, and by the margin of a simulated precinct. Precincts hold more of the votes in landslides and fewer in close contests. Precincts decided by 40 points or more held 36.4% of votes, against 25.4% for counties decided by that margin.

Table 2. Precincts are more often lopsided, and less often close, than counties or than random assignment of voters would make them

Because each county margin is the average of its precinct margins weighted by their votes, precinct margins are at least as spread out as county margins, counting each vote once. That alone does not put more votes in landslide precincts, since a county decided by a landslide can split into precincts of which some are not. The simulation is a benchmark for how much of the gap chance alone would produce. In each of 200 runs, every precinct keeps its number of votes and its county's Democratic share, and its Democratic votes are drawn at random. The simulated precincts hold 56.6% of votes in landslide precincts, 23.3% in close ones and 25.0% in very lopsided ones, within about 0.7 points of the county shares. Each share moves by at most 0.4 points from run to run. Small units alone therefore do not produce the gap between precincts and counties. Precinct margins inside a county vary more than random assignment of voters would make them.

Random assignment still leaves some spread. If the voters of a county were assigned to its precincts at random, the spread would be 3.1 points on average across counties, weighted by votes, and 3.4 points in the median near-tied county.

Spread is widest in Mississippi and Alabama

Across the 2,853 counties with at least 5 reporting units, the median county, counted once, has a spread of 15.6 (95% CI 15.0 to 16.0) points. That is lower than the vote-weighted mean because counties with more votes tend to have wider spreads, as the next sections show. A spread of 30 points or more occurs in 368 counties, which hold 18.7% of the votes cast in the 2,853 counties. Table 3 maps the spread, and its second view maps the county margin.

Table 3. Spread inside counties is widest in Mississippi and Alabama and scattered across the Southwest and Plains

The vote-weighted mean spread is 38.2 (95% CI 34.9 to 41.5) points in Mississippi and 32.2 (95% CI 25.2 to 38.3) in Alabama, the two highest of the 48 states and the District of Columbia. The units that election offices report differ in size by state. The median precinct holds 227 two-party votes in Kansas and 2,083 in Connecticut, and California reports 578 precincts per county on average while North Dakota reports 7. Smaller units can show more spread, so a comparison of spread across states mixes the electorate with the way votes are counted. Counties with few reporting units also have spreads that one unit can move a long way. Of the 33 counties with a spread of 50 points or more, 4 have fewer than 10 reporting units. The state controls in Table 6 address part of that mix.

Among the 318 counties with at least 100,000 two-party votes, the widest spreads are in Kings County, New York (54.9 points), Jefferson County, Alabama (53.5) and Mobile County, Alabama (50.2). The narrowest are in Arlington County, Virginia (6.5) and the District of Columbia (5.9), whose margins are +59.9 and +86.6 points.

Spread falls from metro to less urban counties

Table 4 groups counties by Rural-Urban Continuum Code. The vote-weighted mean spread falls from 24.8 (95% CI 23.5 to 26.1) points in the largest metro counties to 22.7 in smaller metro counties, 19.4 in the larger nonmetro counties and 15.5 (95% CI 14.6 to 16.5) in the least urban ones. The two ends of the scale also differ in lean. The vote-weighted mean margin is +11.7 (95% CI 7.3 to 15.7) points in the largest metro counties and −45.2 (95% CI −47.6 to −42.7) in the least urban, so the next section separates lean from size. The demographics panel has no code for 10 counties, which are left out of the bars: the Connecticut counties, Kansas City, Missouri, and Oglala Lakota County, South Dakota.

Table 4. Spread of precinct margins falls from the largest metro counties to the least urban ones

Spread rises with Democratic lean, partly through county size

Table 5 plots each county's spread against its margin. Weighted by votes, the correlation is +0.41 (95% CI 0.33 to 0.49) across 2,853 counties. The binned means rise from 6.7 (95% CI 5.2 to 8.0) points in counties near Trump +82 to 25.4 (95% CI 23.4 to 27.5) in counties near Trump +14. The 6 bins from there to Harris +34 have means between 24.1 and 28.4. The highest bin, 31.1 (95% CI 24.7 to 36.8) near Harris +43, has an interval that overlaps each of them. The interval for its difference from each of them includes zero, except for the lowest, near Trump +4, where the difference is 6.9 (95% CI 0.7 to 12.9) points. The data show a rise and then a plateau, with the highest bin distinguishable from only the lowest of the bins before it. The 12 counties near Harris +66 average 19.3 (95% CI 15.3 to 23.9), which is 11.8 (95% CI 3.9 to 18.9) points below the highest bin, and few counties are that blue.

Table 5. Spread rises from the reddest counties to about Trump +14, then levels off

Bluer counties are also larger. The correlation of county margin with the log of two-party votes (the natural logarithm, so that each doubling of a county's votes adds the same amount) is +0.64 (95% CI 0.59 to 0.69), in line with the concentration of Democratic voters in dense places [4]. The correlation of spread with the log of votes is +0.40 (95% CI 0.33 to 0.46). Larger counties have more precincts, and with more precincts there is more room for very different ones. Table 6 holds fixed the log of a county's votes and the log of its number of precincts, and the correlation of lean with spread falls from +0.41 to +0.21 (95% CI 0.12 to 0.30). It then adds state fixed effects, which compare counties within the same state and so absorb each state's own precinct conventions, and the correlation is +0.28 (95% CI 0.19 to 0.37). With both controls, a county 10 points more Democratic has a spread 0.9 (95% CI 0.6 to 1.3) points wider, against 1.1 (95% CI 0.8 to 1.4) points without them. The correlation is also positive when each county counts once, so its sign does not depend on the vote weights.

Table 6. Spread rises with Democratic lean, with or without controls for county size and state

Two county characteristics measured outside the vote show a similar pattern. Across 2,843 counties with demographic data, which leaves out the Connecticut counties, spread correlates +0.43 (95% CI 0.36 to 0.50) with the nonwhite share of residents (the share who are not non-Hispanic white, American Community Survey, 2024). It correlates −0.36 (95% CI −0.41 to −0.30) with the rural share (the share living outside urban areas as the 2020 Census defines them). With size and state held fixed the two are +0.31 (95% CI 0.22 to 0.40) and −0.13 (95% CI −0.19 to −0.08), so the tie to the nonwhite share weakens less than the tie to the rural share does.

Spread falls with distance from an even split

Distance from an even split is the size of a county's margin, whichever party leads. One might expect the counties closest to a tie to be the most divided, because a near-tied county needs votes from precincts on both sides. Across all counties, the correlation of spread with distance from an even split is −0.29 (95% CI −0.39 to −0.20) when weighted by votes, and it stays negative with size and state held fixed, at −0.19 and −0.25. Counting each county once, it is −0.55 (95% CI −0.57 to −0.52). Spread is lower in counties that are farther from an even split.

Among the 1,725 counties with a margin of 50 points or less, the vote-weighted correlation is −0.04 (95% CI −0.18 to 0.08), an interval that includes zero, against −0.26 (95% CI −0.30 to −0.22) when each county counts once. The vote-weighted result depends on the cutoff, as Table 7 shows. Its interval excludes zero only from 60 points up, where the correlation is −0.15. The absence of a link is specific to the vote-weighted comparison of counties within 50 points or less, and it is not a finding about counties in general.

Table 7. Spread falls with distance from an even split, except in vote-weighted comparisons of counties within 50 points

The negative correlation grows as the tails are added. Precinct margins cannot pass 100 points in either direction, so a county with a margin near the limit has little room for spread. Among the 260 counties with a margin beyond 70 points, however, the widest spread is 34.7 points, against a limit of 71.4 at a margin of 70 points. The highest ratio of a county's spread to the limit at its own margin is 49%.The largest spread a county can have is the square root of 100 squared minus its margin squared, so it falls to zero as the margin approaches 100. Among the 260 counties beyond 70 points, the mean ratio of a county's spread to the limit at its own margin is 12%. The limit therefore does not account for the low spread in lopsided counties, and the data cannot say what does. One candidate is that the losing party has few precincts in those counties, and another is that margins are compressed near one side of the scale well short of the mathematical limit. This chapter reports the pattern and does not read the negative correlation as a finding about competitiveness. The link of spread to Democratic lean does not come from the tails. Within 50 points the correlation of spread with lean is +0.41 (95% CI 0.32 to 0.49), against +0.41 (95% CI 0.33 to 0.49) across all counties.

Near-tied counties differ widely in spread

A near-tied county has a margin under 5 points and at least 20 precincts. The group has 111 counties with 18.9 million two-party votes. Table 8 shows their spreads. The median is 23.9 (95% CI 22.8 to 24.9) points, against 3.4 for the median county if voters were assigned to precincts at random, and the range runs from 10.1 to 58.1. A spread of 30 points or more occurs in 29 counties, 26.1% of the group.

Table 8. Near-tied counties differ widely in how much their precinct margins vary

The median near-tied spread is above the 15.6 of all counties. Near-tied counties are larger, though, with a median of 78,269 two-party votes against 13,707 for the median county with a spread, and larger counties have wider spreads. The comparison of the two medians therefore mixes closeness with size.

Their votes are spread across the range of precinct margins. Near-tied counties cast 35.6% of their votes in precincts decided by under 10 points, against 18.5% in all precincts, and 38.2% in precincts decided by 20 points or more, against 65.0%. The landslide share divides into 17.5% in Democratic precincts and 20.7% in Republican ones, and precincts decided by 40 points or more held 10.5%. A county built from two landslides would have at least 20% of its votes in Democratic landslide precincts and at least 20% in Republican ones. Of the 111 counties, 39 (35.1%) meet that test. The near-tied counties as a group hold more of their votes in close precincts than the country does and fewer in landslide precincts, and they differ from one another in how the votes divide.

The counties in Table 1 fall at different points of this range. Bucks County, with a spread of 14.8, is in the lowest bin of Table 8, and Centre County, at 36.3, is past the 30-point line.

What these data cannot show

The chapter describes one election. It says nothing about whether precinct margins are spreading or narrowing, and it makes no comparison with earlier years. Planned, Sorting by geographic scale, 2016 to 2024 (planned), a planned chapter, will compare precincts across elections, and Chapter 6.1, Nationalization of the county vote measures how closely county results move together from one election to the next.

A precinct is a reporting unit and not a neighborhood. The file has no boundaries, so the data cannot say which precincts are adjacent, and a county with a wide spread need not have opposed precincts next to each other. Units also differ in kind. Units labelled absentee, provisional, early voting, mail, failsafe, military or overseas, and units labelled as statistical adjustments, hold 1.5% of votes across 870 units, and they are buckets of ballots and not places. Table 9 repeats the main statistics without them and without the counties where they hold 20% of votes or more. That leaves 2,721 counties with a spread and 106 near-tied counties, against 111 in the full sample.

Table 9. Dropping ballot-bucket units moves each correlation by at most 0.02 and each vote share by at most 0.3 points

A precinct margin describes a place and not the voters in it. A precinct that gave one party 60% or more still holds voters of the other. Ecological inference, which moves from places to individuals, can fail, because a pattern across places can differ from the pattern among individuals [5]. The results also depend on the units. Shares and spreads change with the size and shape of the areas, a problem known as the modifiable areal unit problem [6], and this chapter uses the units that election offices happened to report. The 64 Louisiana parishes, the 6 other counties and Alaska that are left out are not a random set. The cutoffs for near-tied counties and for a wide spread are choices, and so are the vote weights and the 50-point cutoff behind the correlation of spread with distance from an even split. That correlation is near zero only in the vote-weighted comparisons within 50 points or less. A single spread cannot tell a county with two humps from a county with a long tail. The random-assignment benchmark holds each unit's size and its county's margin fixed and does not model why voters differ across precincts. Nothing here identifies why spread is wider in some counties. It goes with lean, size, nonwhite share and place type, and the controls are few and linear.

Tables

Table 1. Bucks County precincts cluster near an even split, while Centre County precincts form two groups, one on each side

Share of each county's 2024 two-party votes cast in precincts in each 10-point band of margin

county	n	share	x0	x1
Bucks County, PA	0	0	−100	−90
Bucks County, PA	0	0	−90	−80
Bucks County, PA	0	0	−80	−70
Bucks County, PA	0	0	−70	−60
Bucks County, PA	0	0	−60	−50
Bucks County, PA	0	0	−50	−40
Bucks County, PA	4	1.05	−40	−30
Bucks County, PA	25	8.35	−30	−20
Bucks County, PA	54	17.71	−20	−10
Bucks County, PA	83	27.62	−10	0
Bucks County, PA	68	22.48	0	10
Bucks County, PA	40	13.77	10	20
Bucks County, PA	15	5.06	20	30
Bucks County, PA	13	3.63	30	40
Bucks County, PA	2	0.315	40	50
Bucks County, PA	0	0	50	60
Bucks County, PA	0	0	60	70
Bucks County, PA	0	0	70	80
Bucks County, PA	0	0	80	90
Bucks County, PA	0	0	90	100
Centre County, PA	0	0	−100	−90
Centre County, PA	0	0	−90	−80
Centre County, PA	1	0.333	−80	−70
Centre County, PA	5	4.17	−70	−60
Centre County, PA	8	6.12	−60	−50
Centre County, PA	12	6.15	−50	−40
Centre County, PA	7	7.06	−40	−30
Centre County, PA	8	10.56	−30	−20
Centre County, PA	5	5.43	−20	−10
Centre County, PA	3	4.12	−10	0
Centre County, PA	2	1.34	0	10
Centre County, PA	7	11.96	10	20
Centre County, PA	8	14.10	20	30
Centre County, PA	7	12.99	30	40
Centre County, PA	7	9.71	40	50
Centre County, PA	3	2.83	50	60
Centre County, PA	4	3.13	60	70
Centre County, PA	0	0	70	80
Centre County, PA	0	0	80	90
Centre County, PA	0	0	90	100

Note: The number in the tooltip is the number of precincts in the band. The two counties were chosen for the contrast between them, not at random.

Note: Full counts of votes: there is no sampling, so the shares carry no confidence interval.

Source: MIT Election Data and Science Lab, 2024 precinct-level presidential returns; county totals summed from the precincts; full counts of votes, not survey estimates, so nothing is weighted except by two-party votes where stated

Data: vishalsingh.org/politics/report/precincts-within-counties/figures/example_counties.json

Table 2. Precincts are more often lopsided, and less often close, than counties or than random assignment of voters would make them

Share of 2024 two-party presidential votes cast in units decided by each margin, in percent of votes

band	share	unit
Under 10 points	18.52	Precincts
Under 10 points	23.13	Counties
Under 10 points	23.32	Simulated precincts
20 points or more	64.97	Precincts
20 points or more	57.25	Counties
20 points or more	56.58	Simulated precincts
40 points or more	36.37	Precincts
40 points or more	25.38	Counties
40 points or more	24.96	Simulated precincts

Note: Full counts of votes: there is no sampling, so the shares carry no confidence interval.

Note: The simulated bars are means over 200 runs and move by at most 0.4 points across runs.

Note: The sample is 175,345 reporting units in 3,043 counties: Alaska, the 64 Louisiana parishes and 6 other counties whose precinct rows do not match the certified total are left out.

Data: vishalsingh.org/politics/report/precincts-within-counties/figures/landslide_shares.json

Table 3. Spread inside counties is widest in Mississippi and Alabama and scattered across the Southwest and Plains

Vote-weighted standard deviation of precinct margins inside each county, 2024, in points of two-party margin; counties with at least 5 reporting units

No inline rows: the values of Table 3 are in /data/precincts-within-counties/county_sd_map.json.

Views: Spread inside the county; County margin.

Note: Counties with fewer than 5 reporting units (190 of the 3,043 in the sample), the 64 Louisiana parishes, 6 other counties whose precinct rows do not match the certified total, Alaska and Kansas City, Missouri are drawn as no data.

Note: A county near the floor of 5 reporting units has a spread that one unit can move a long way.

Note: Full counts of votes: there is no sampling, so county margins and spreads carry no sampling error.

Data: vishalsingh.org/politics/report/precincts-within-counties/figures/county_sd_map.json

Table 4. Spread of precinct margins falls from the largest metro counties to the least urban ones

Vote-weighted mean of county spreads by Rural-Urban Continuum Code group, 2024, in points of two-party margin

Place type	Description	Rural-Urban Continuum Code	Mean spread (points)	Interval, low	Interval, high	Counties
Largest metro	Metro area of 1 million or more	1	24.8	23.5	26.1	419
Smaller metro	Smaller metro area	2 to 3	22.7	21.9	23.5	690
Larger nonmetro	Nonmetro, larger towns	4 to 7	19.4	18.7	20.1	861
Least urban	Nonmetro, smaller towns and open country	8 to 9	15.5	14.6	16.5	873

Note: The number in the tooltip is the number of counties in the group. 2,853 counties have at least 5 reporting units; 10 of them have no code in the demographics panel (the Connecticut counties, Kansas City, Missouri, and Oglala Lakota County, South Dakota) and are left out of the bars.

Note: The returns are full counts with no sampling error. The whiskers show how much a mean would move with a different set of counties, from a county bootstrap.

Data: vishalsingh.org/politics/report/precincts-within-counties/figures/sd_by_place_type.json

Table 5. Spread rises from the reddest counties to about Trump +14, then levels off

Vote-weighted standard deviation of precinct margins inside each county against the county two-party margin, 2024; one dot per county, sized by two-party votes

County	Margin (points)	Spread (points)	Two-party votes	Precincts
Autauga, AL	−46.7	17.4	27,923	21
Baldwin, AL	−58.7	16.3	120,732	61
Barbour, AL	−14.8	32.1	9,764	18
Bibb, AL	−64.8	24.6	9,191	10
Blount, AL	−81.6	6.7	27,930	26
Bullock, AL	+46.1	42.8	4,084	10
Butler, AL	−22.8	41.2	8,423	23
Calhoun, AL	−45.1	37.0	48,106	44
Chambers, AL	−23.4	30.5	14,116	18
Cherokee, AL	−75.9	9.7	12,911	25
Chilton, AL	−72.5	15.5	19,618	20
Choctaw, AL	−24.0	55.1	6,618	34
Clarke, AL	−17.1	41.6	11,892	31
Clay, AL	−70.5	19.7	6,727	17
Cleburne, AL	−84.1	8.2	7,593	16
Coffee, AL	−58.4	26.2	22,096	29
Colbert, AL	−46.8	26.4	26,851	36
Conecuh, AL	−14.0	52.0	6,003	28
Coosa, AL	−43.5	48.4	5,236	14
Covington, AL	−72.8	15.1	16,991	27
Crenshaw, AL	−54.9	31.7	6,457	17
Cullman, AL	−81.1	9.6	42,743	51
Dale, AL	−52.7	20.9	18,960	20
Dallas, AL	+32.7	47.3	15,426	31
Dekalb, AL	−74.4	10.2	29,391	46
Elmore, AL	−52.5	22.7	41,148	31
Escambia, AL	−46.6	39.9	14,848	31
Etowah, AL	−56.1	37.1	45,680	33
Fayette, AL	−72.5	21.8	8,300	26
Franklin, AL	−73.8	17.8	11,985	26
Geneva, AL	−77.4	10.6	12,320	23
Greene, AL	+55.9	21.4	4,018	16
Hale, AL	+6.9	37.0	7,237	16
Henry, AL	−51.1	24.4	9,252	16
Houston, AL	−48.2	31.8	43,821	30
Jackson, AL	−71.9	8.8	23,349	32
Jefferson, AL	+10.6	53.5	293,235	179
Lamar, AL	−76.4	15.6	6,839	27
Lauderdale, AL	−52.0	27.6	43,034	33
Lawrence, AL	−62.7	37.2	16,007	31
Lee, AL	−28.2	28.7	71,818	27
Limestone, AL	−44.4	24.2	52,468	27
Lowndes, AL	+37.5	44.6	5,625	14
Macon, AL	+56.7	38.4	7,766	16
Madison, AL	−9.1	31.9	193,254	81
Marengo, AL	−3.8	38.7	9,626	20
Marion, AL	−82.2	4.1	13,442	17
Marshall, AL	−72.2	7.1	39,987	31
Mobile, AL	−16.6	50.2	172,814	82
Monroe, AL	−23.3	50.6	9,747	29
Montgomery, AL	+31.1	40.0	88,423	53
Morgan, AL	−53.1	31.9	52,841	41
Perry, AL	+42.9	46.9	4,443	14
Pickens, AL	−23.5	47.9	8,853	21
Pike, AL	−25.3	41.8	13,123	36
Randolph, AL	−65.2	23.0	11,022	22
Russell, AL	+1.7	40.2	20,500	20
St. Clair, AL	−64.6	14.0	43,141	32
Shelby, AL	−41.3	16.8	112,753	40
Sumter, AL	+41.4	23.8	5,267	15
Talladega, AL	−33.9	30.2	32,998	28
Tallapoosa, AL	−49.9	37.2	19,859	28
Tuscaloosa, AL	−20.6	47.1	84,123	56
Walker, AL	−72.3	16.2	29,566	47
Washington, AL	−55.6	35.8	8,397	21
Wilcox, AL	+31.6	48.9	5,242	21
Winston, AL	−84.0	4.8	11,075	20
Apache, AZ	+19.2	57.9	31,667	44
Cochise, AZ	−23.4	26.6	58,232	54
Coconino, AZ	+20.2	34.4	69,080	75
Gila, AZ	−37.9	28.2	27,405	39
Graham, AZ	−48.6	34.3	15,044	23
Greenlee, AZ	−41.5	17.5	3,262	6
La Paz, AZ	−44.5	22.5	7,571	11
Maricopa, AZ	−3.5	24.2	2,031,547	907
Mohave, AZ	−56.1	9.4	109,725	24
Navajo, AZ	−17.4	52.7	50,234	17
Pima, AZ	+15.3	24.6	507,119	265
Pinal, AZ	−22.3	17.9	207,582	108
Santa Cruz, AZ	+18.8	19.2	18,950	31
Yavapai, AZ	−34.0	20.9	147,083	54
Yuma, AZ	−20.6	24.2	67,568	44
Arkansas, AR	−44.9	39.5	5,454	30
Ashley, AR	−48.7	40.0	6,919	30
Baxter, AR	−57.8	5.8	20,594	11
Benton, AR	−27.7	20.6	124,948	426
Boone, AR	−66.1	9.1	16,822	12
Bradley, AR	−39.4	44.8	3,174	14
Calhoun, AR	−63.1	18.1	2,053	8
Carroll, AR	−32.4	33.2	11,282	11
Chicot, AR	+4.0	49.0	3,454	7
Clark, AR	−20.9	35.2	7,485	20
Clay, AR	−62.8	9.1	4,875	17
Cleburne, AR	−69.0	9.7	12,536	34
Cleveland, AR	−68.5	22.5	3,328	17
Columbia, AR	−37.0	35.1	7,833	14
Conway, AR	−41.3	25.2	8,342	31
Craighead, AR	−38.3	27.2	36,362	53
Crawford, AR	−59.3	7.5	23,368	13
Crittenden, AR	+2.3	41.8	14,390	17
Cross, AR	−48.6	40.6	6,395	14
Dallas, AR	−30.0	47.2	2,280	9
Desha, AR	−4.9	45.7	3,443	21
Drew, AR	−34.4	29.2	6,253	17
Faulkner, AR	−33.1	29.8	53,109	51
Franklin, AR	−63.8	9.4	6,814	39
Fulton, AR	−63.4	9.0	4,946	10
Garland, AR	−37.1	20.5	41,374	52
Grant, AR	−70.0	9.4	7,947	18
Greene, AR	−62.3	8.9	15,552	11
Hempstead, AR	−40.5	41.1	5,969	24
Hot Spring, AR	−53.2	29.0	12,044	32
Howard, AR	−47.4	34.8	4,404	9
Independence, AR	−60.8	17.1	13,712	34
Izard, AR	−67.3	9.2	5,803	45
Jackson, AR	−49.6	30.7	4,692	45
Jefferson, AR	+20.4	59.6	21,270	169
Johnson, AR	−52.5	12.6	8,873	11
Lafayette, AR	−39.0	42.9	2,287	9
Lawrence, AR	−65.4	9.2	5,573	28
Lee, AR	+3.6	43.2	2,451	9
Lincoln, AR	−51.0	51.2	3,315	26
Little River, AR	−55.1	27.9	4,828	20
Logan, AR	−63.5	9.4	8,031	36
Lonoke, AR	−54.8	20.0	30,015	55
Madison, AR	−59.6	6.2	7,376	10
Marion, AR	−61.2	9.2	7,731	29
Miller, AR	−51.7	35.1	15,611	19
Mississippi, AR	−32.2	45.1	10,537	16
Monroe, AR	−16.0	48.4	2,387	24
Montgomery, AR	−64.5	9.0	3,632	16
Nevada, AR	−40.4	43.2	2,851	20
Newton, AR	−65.3	18.2	3,707	19
Ouachita, AR	−19.4	38.3	8,468	18
Perry, AR	−58.8	9.1	4,482	17
Phillips, AR	+13.5	39.5	4,852	10
Pike, AR	−74.0	14.3	4,306	11
Poinsett, AR	−64.5	9.4	6,966	12
Polk, AR	−71.8	7.5	8,132	17
Pope, AR	−53.5	18.9	23,605	55
Prairie, AR	−66.8	16.1	3,152	24
Pulaski, AR	+22.7	35.3	150,015	132
Randolph, AR	−65.0	10.6	6,505	29
St Francis, AR	+0.8	53.8	5,862	15
Saline, AR	−41.0	20.1	56,345	42
Scott, AR	−74.5	10.5	3,338	26
Searcy, AR	−73.2	8.1	3,816	15
Sebastian, AR	−38.5	27.2	44,371	180
Sevier, AR	−62.8	18.8	4,634	9
Sharp, AR	−63.9	10.4	7,294	25
Stone, AR	−63.1	7.6	5,897	18
Union, AR	−34.0	41.0	15,215	28
Van Buren, AR	−61.5	11.9	7,460	21
Washington, AR	−6.9	33.1	94,022	224
White, AR	−62.6	14.1	30,155	92
Woodruff, AR	−33.1	45.0	2,273	20
Yell, AR	−61.9	16.1	6,360	28
Alameda, CA	+56.0	26.1	640,028	822
Alpine, CA	+32.7	20.6	722	5
Amador, CA	−28.5	20.3	21,742	79
Butte, CA	−3.1	31.4	91,203	212
Calaveras, CA	−28.8	25.8	25,806	50
Colusa, CA	−29.0	20.6	6,845	19
Contra Costa, CA	+39.3	24.3	510,211	1,202
Del Norte, CA	−16.8	18.1	10,257	36
El Dorado, CA	−12.3	25.0	108,695	260
Fresno, CA	−4.5	27.6	316,996	684
Glenn, CA	−35.7	27.4	9,928	113
Humboldt, CA	+29.8	30.0	61,284	164
Imperial, CA	−0.7	23.3	52,228	215
Inyo, CA	−2.9	19.6	8,650	28
Kern, CA	−21.6	26.4	275,461	1,082
Kings, CA	−23.4	21.6	40,435	174
Lake, CA	−1.4	14.4	25,945	73
Lassen, CA	−55.2	16.0	10,972	65
Los Angeles, CA	+34.0	29.4	3,605,749	4,808
Madera, CA	−21.3	21.1	53,240	112
Marin, CA	+65.7	14.9	140,102	217
Mariposa, CA	−21.5	25.8	9,159	32
Mendocino, CA	+28.1	25.1	37,197	240
Merced, CA	−3.9	28.4	82,772	621
Modoc, CA	−48.1	14.3	3,874	30
Mono, CA	+21.1	31.4	5,808	22
Monterey, CA	+30.8	20.8	142,286	403
Napa, CA	+36.1	17.7	63,325	336
Nevada, CA	+12.7	31.3	59,904	180
Orange, CA	+2.8	25.4	1,346,071	2,899
Placer, CA	−8.7	23.9	227,596	468
Plumas, CA	−17.5	20.0	9,745	28
Riverside, CA	−1.3	24.9	914,400	1,711
Sacramento, CA	+20.4	27.2	633,476	1,249
San Benito, CA	+12.9	22.8	26,881	80
San Bernardino, CA	−2.1	24.1	738,081	2,738
San Diego, CA	+17.3	26.6	1,433,911	3,315
San Francisco, CA	+67.6	18.0	386,298	1,014
San Joaquin, CA	−0.9	25.2	255,429	437
San Luis Obispo, CA	+11.2	28.3	146,169	251
San Mateo, CA	+52.1	15.9	319,349	523
Santa Barbara, CA	+27.6	31.9	178,735	424
Santa Clara, CA	+41.6	20.7	721,284	1,311
Santa Cruz, CA	+56.6	17.8	128,801	282
Shasta, CA	−37.4	16.0	86,661	128
Sierra, CA	−24.9	22.6	1,707	19
Siskiyou, CA	−19.9	29.1	20,790	105
Solano, CA	+23.8	24.9	184,102	366
Sonoma, CA	+47.8	14.5	242,395	755
Stanislaus, CA	−11.2	22.6	192,155	469
Sutter, CA	−32.2	14.8	38,388	48
Tehama, CA	−42.7	16.5	25,869	68
Trinity, CA	−9.8	13.5	5,428	14
Tulare, CA	−21.2	24.3	135,075	584
Tuolumne, CA	−22.4	17.8	28,098	78
Ventura, CA	+15.6	24.4	374,949	1,715
Yolo, CA	+37.6	31.3	89,249	95
Yuba, CA	−26.6	20.2	29,216	63
Adams, CO	+9.3	20.1	227,080	275
Alamosa, CO	−11.1	20.4	7,301	8
Arapahoe, CO	+20.7	16.7	316,036	394
Archuleta, CO	−14.4	9.9	9,122	8
Baca, CO	−72.0	7.4	1,961	9
Bent, CO	−39.7	24.7	2,141	5
Boulder, CO	+57.3	17.6	190,907	190
Broomfield, CO	+29.4	10.9	45,497	58
Chaffee, CO	+14.0	20.3	14,026	11
Cheyenne, CO	−79.2	10.3	1,038	5
Clear Creek, CO	+17.1	9.3	5,916	9
Conejos, CO	−18.3	27.8	3,985	10
Costilla, CO	+15.2	23.8	2,005	8
Crowley, CO	−48.9	4.9	1,653	6
Delta, CO	−36.5	23.3	18,978	20
Denver, CO	+57.7	16.6	353,399	301
Douglas, CO	−7.2	14.3	237,859	204
Eagle, CO	+25.1	17.1	27,091	34
Elbert, CO	−52.3	8.5	19,977	18
El Paso, CO	−10.1	21.0	370,530	324
Fremont, CO	−39.4	9.3	24,839	20
Garfield, CO	+2.1	38.2	29,621	27
Gilpin, CO	+13.2	16.6	3,983	6
Grand, CO	−0.8	28.9	9,565	12
Gunnison, CO	+30.2	31.2	10,576	15
Huerfano, CO	−8.8	9.5	4,311	5
Jefferson, CO	+20.0	14.1	351,380	296
Kit Carson, CO	−69.4	7.6	3,639	13
Lake, CO	+17.1	7.9	3,756	6
La Plata, CO	+19.2	33.6	34,701	33
Larimer, CO	+18.1	25.8	219,056	155
Las Animas, CO	−13.8	21.7	7,604	7
Lincoln, CO	−65.7	7.5	2,522	13
Logan, CO	−57.8	15.9	9,953	16
Mesa, CO	−24.9	19.2	89,412	67
Moffat, CO	−64.2	9.5	6,525	13
Montezuma, CO	−21.5	21.8	14,765	12
Montrose, CO	−33.3	17.0	25,058	21
Morgan, CO	−49.8	15.6	13,121	18
Otero, CO	−27.1	24.2	8,684	17
Ouray, CO	+21.6	23.8	4,015	5
Park, CO	−17.0	17.1	11,669	13
Phillips, CO	−64.2	8.7	2,300	8
Pitkin, CO	+45.2	5.2	10,924	12
Prowers, CO	−51.5	11.6	5,060	5
Pueblo, CO	−5.3	24.3	83,016	144
Rio Blanco, CO	−64.9	9.8	3,625	5
Rio Grande, CO	−23.8	18.5	6,049	15
Routt, CO	+28.5	26.9	15,884	19
Saguache, CO	+3.9	34.0	3,281	7
San Miguel, CO	+50.7	30.0	4,683	6
Sedgwick, CO	−57.5	7.5	1,331	5
Summit, CO	+38.3	8.9	17,006	20
Teller, CO	−36.4	5.6	15,921	14
Washington, CO	−76.2	4.3	2,765	6
Weld, CO	−21.5	21.9	175,221	184
Yuma, CO	−66.8	8.3	4,565	14
Fairfield, CT	+19.9	17.6	445,282	190
Hartford, CT	+22.9	23.7	421,938	167
Litchfield, CT	−8.2	20.7	104,392	48
Middlesex, CT	+13.1	13.5	95,827	33
New Haven, CT	+12.2	27.5	390,416	204
New London, CT	+12.8	17.2	135,048	54
Tolland, CT	+8.2	18.5	80,084	28
Windham, CT	−10.4	17.3	55,984	32
Kent, DE	+2.0	30.3	86,680	98
New Castle, DE	+33.1	23.3	271,568	312
Sussex, DE	−11.1	23.7	145,861	119
District of Columbia, DC	+86.6	5.9	315,261	144
Alachua, FL	+21.3	29.3	134,517	63
Baker, FL	−73.4	12.3	14,908	9
Bay, FL	−47.9	17.0	96,698	29
Bradford, FL	−57.5	28.2	13,866	13
Brevard, FL	−21.0	13.4	357,766	150
Broward, FL	+17.1	26.3	866,280	358
Calhoun, FL	−68.0	22.5	6,388	10
Charlotte, FL	−34.2	10.4	122,930	81
Citrus, FL	−46.2	7.7	97,632	32
Clay, FL	−39.6	24.6	125,637	48
Collier, FL	−33.3	12.6	214,987	67
Columbia, FL	−50.5	21.0	33,358	26
Desoto, FL	−43.2	28.7	12,413	15
Dixie, FL	−70.8	13.2	8,103	10
Duval, FL	−1.5	31.3	465,650	160
Escambia, FL	−19.8	28.8	161,008	80
Flagler, FL	−28.4	9.5	79,445	21
Franklin, FL	−44.2	28.6	6,701	8
Gadsden, FL	+30.9	39.8	21,698	25
Gilchrist, FL	−68.6	7.2	10,593	10
Glades, FL	−53.5	24.5	5,256	13
Gulf, FL	−54.5	24.1	8,654	10
Hamilton, FL	−39.3	30.8	5,691	8
Hardee, FL	−56.7	23.6	8,088	12
Hendry, FL	−38.6	29.0	13,349	10
Hernando, FL	−37.3	9.7	109,877	32
Highlands, FL	−41.0	17.3	51,609	25
Hillsborough, FL	−3.1	24.2	663,472	448
Holmes, FL	−80.6	4.5	9,075	8
Indian River, FL	−27.5	10.9	98,391	34
Jackson, FL	−46.4	25.2	21,966	14
Jefferson, FL	−18.7	20.3	8,440	16
Lafayette, FL	−76.4	15.5	3,737	5
Lake, FL	−24.9	17.6	225,046	92
Lee, FL	−28.6	13.8	389,901	99
Leon, FL	+22.0	29.8	154,917	132
Levy, FL	−50.5	14.5	24,239	13
Liberty, FL	−67.3	30.8	3,464	8
Madison, FL	−29.0	34.1	9,105	11
Manatee, FL	−23.7	15.2	227,160	71
Marion, FL	−31.9	17.7	212,609	106
Martin, FL	−31.3	10.8	97,660	28
Miami-Dade, FL	−11.5	34.0	1,085,945	721
Monroe, FL	−18.5	22.9	43,997	33
Nassau, FL	−47.3	22.6	65,088	18
Okaloosa, FL	−42.9	15.4	112,383	52
Okeechobee, FL	−54.1	10.9	15,986	11
Orange, FL	+13.8	21.1	599,086	257
Osceola, FL	−1.5	20.2	170,918	127
Palm Beach, FL	+0.8	23.9	739,348	781
Pasco, FL	−25.5	12.8	315,229	120
Pinellas, FL	−5.3	22.8	511,924	286
Polk, FL	−20.9	23.0	345,923	172
Putnam, FL	−48.1	27.6	36,054	37
St. Johns, FL	−31.6	11.1	195,621	53
St. Lucie, FL	−9.1	18.9	183,810	61
Santa Rosa, FL	−51.4	11.7	111,349	41
Sarasota, FL	−18.3	16.8	275,887	103
Seminole, FL	−3.6	14.8	250,452	82
Sumter, FL	−37.8	8.9	104,685	30
Suwannee, FL	−61.3	18.6	21,778	14
Taylor, FL	−60.0	35.5	9,945	14
Union, FL	−68.7	7.0	6,195	8
Volusia, FL	−21.9	19.0	307,823	143
Wakulla, FL	−44.7	7.9	19,687	12
Walton, FL	−58.2	9.9	49,257	21
Washington, FL	−65.8	15.0	12,510	12
Appling, GA	−62.5	36.4	8,321	9
Baker, GA	−19.9	24.0	1,473	5
Baldwin, GA	−2.2	35.8	18,733	14
Banks, GA	−78.3	3.8	10,494	13
Barrow, GA	−40.7	11.2	43,679	8
Bartow, GA	−51.3	13.9	57,213	17
Berrien, GA	−70.0	7.4	8,050	5
Bibb, GA	+22.5	40.6	68,830	31
Brooks, GA	−26.9	30.5	7,189	7
Bryan, GA	−36.5	16.0	24,517	10
Bulloch, GA	−29.1	28.5	32,499	16
Burke, GA	−9.4	24.6	11,021	16
Calhoun, GA	+12.3	32.5	2,053	5
Camden, GA	−35.9	12.4	26,224	11
Carroll, GA	−41.4	25.7	60,170	28
Catoosa, GA	−55.8	6.7	34,854	11
Charlton, GA	−56.4	25.1	4,614	6
Chatham, GA	+18.1	38.5	140,094	87
Chattooga, GA	−64.4	9.1	10,665	7
Cherokee, GA	−39.3	15.3	160,980	42
Clarke, GA	+38.7	16.1	52,346	24
Clay, GA	+7.5	32.0	1,434	5
Clayton, GA	+69.6	13.5	111,080	70
Clinch, GA	−51.6	14.2	2,903	5
Cobb, GA	+15.0	26.6	397,083	148
Coffee, GA	−45.2	15.7	15,683	6
Colquitt, GA	−50.3	35.0	16,565	19
Columbia, GA	−25.8	21.5	85,281	46
Cook, GA	−46.6	35.4	7,330	8
Coweta, GA	−34.1	22.6	85,315	24
Crawford, GA	−50.0	29.3	6,324	5
Crisp, GA	−26.0	39.3	8,092	5
Dade, GA	−67.0	9.1	8,147	7
Decatur, GA	−24.0	27.9	11,512	10
Dekalb, GA	+65.4	24.7	362,252	191
Dodge, GA	−50.0	21.6	8,330	16
Dooly, GA	−7.7	13.6	4,164	5
Dougherty, GA	+41.3	36.0	33,735	25
Douglas, GA	+31.7	32.1	70,236	25
Early, GA	−11.5	37.5	4,876	5
Effingham, GA	−49.3	12.0	36,087	20
Elbert, GA	−43.5	23.5	9,560	11
Emanuel, GA	−44.3	23.7	9,592	11
Fannin, GA	−65.0	5.0	16,039	12
Fayette, GA	−3.2	32.7	73,999	36
Floyd, GA	−42.2	25.2	44,493	19
Forsyth, GA	−33.5	16.9	136,790	29
Franklin, GA	−72.8	8.4	12,106	7
Fulton, GA	+45.4	38.7	529,389	450
Gilmer, GA	−62.9	4.9	18,389	13
Glynn, GA	−26.1	29.2	43,702	17
Gordon, GA	−63.7	13.3	27,477	12
Grady, GA	−38.4	40.4	10,675	13
Greene, GA	−29.1	25.6	12,729	5
Gwinnett, GA	+16.7	21.3	415,548	156
Habersham, GA	−65.2	6.0	23,178	6
Hall, GA	−44.1	22.0	101,338	31
Hancock, GA	+35.5	33.4	4,228	10
Haralson, GA	−74.7	6.9	16,304	12
Harris, GA	−46.3	12.1	22,259	12
Hart, GA	−55.0	12.1	14,274	7
Heard, GA	−72.3	8.4	6,194	6
Henry, GA	+29.8	31.3	128,235	37
Houston, GA	−11.3	23.5	80,997	17
Jeff Davis, GA	−68.5	25.6	5,859	9
Jefferson, GA	−1.2	26.3	7,439	8
Jenkins, GA	−30.6	37.0	3,396	5
Jones, GA	−38.2	25.0	16,038	10
Laurens, GA	−32.8	36.7	23,280	15
Lee, GA	−43.7	11.7	17,612	10
Liberty, GA	+17.5	25.7	22,900	12
Lincoln, GA	−45.0	23.6	4,910	7
Long, GA	−29.6	17.9	7,033	7
Lowndes, GA	−18.1	35.3	47,568	18
McDuffie, GA	−25.0	41.4	10,499	7
McIntosh, GA	−28.7	25.4	7,375	5
Macon, GA	+18.0	24.0	4,671	5
Madison, GA	−55.1	18.5	16,704	12
Marion, GA	−30.4	44.3	3,601	5
Meriwether, GA	−25.6	25.4	11,748	14
Mitchell, GA	−16.4	39.9	8,851	11
Monroe, GA	−46.8	27.1	17,643	14
Morgan, GA	−46.2	28.5	13,122	5
Murray, GA	−71.8	5.0	17,424	7
Muscogee, GA	+23.5	40.3	80,029	25
Newton, GA	+15.2	39.9	58,732	19
Oconee, GA	−36.3	11.8	27,044	8
Paulding, GA	−24.3	21.1	94,571	21
Peach, GA	−6.1	36.1	13,397	7
Pickens, GA	−66.1	9.0	20,803	12
Pierce, GA	−77.6	9.0	9,744	8
Pike, GA	−73.7	7.9	12,512	8
Polk, GA	−60.7	14.7	19,101	7
Putnam, GA	−42.4	25.2	12,832	5
Randolph, GA	+7.7	28.5	2,974	6
Richmond, GA	+36.3	38.6	83,129	68
Rockdale, GA	+47.8	20.9	44,876	16
Screven, GA	−25.3	28.7	6,906	7
Seminole, GA	−40.5	46.9	4,002	5
Spalding, GA	−16.8	38.4	32,863	17
Sumter, GA	+2.2	38.7	12,005	11
Talbot, GA	+12.0	27.3	3,371	7
Tattnall, GA	−53.6	13.7	8,482	8
Telfair, GA	−39.4	24.1	4,204	6
Terrell, GA	+4.1	42.3	4,328	6
Thomas, GA	−24.2	39.7	22,017	20
Tift, GA	−35.8	39.4	16,934	12
Toombs, GA	−50.9	17.8	10,882	5
Troup, GA	−24.5	36.5	31,149	13
Twiggs, GA	−14.7	34.9	4,444	5
Union, GA	−62.8	4.1	17,786	11
Walker, GA	−59.6	10.7	31,898	11
Walton, GA	−46.2	20.7	58,012	19
Ware, GA	−43.3	46.6	14,347	13
Washington, GA	−1.9	20.9	9,467	8
Wayne, GA	−59.9	29.0	13,519	12
White, GA	−68.8	8.9	16,745	10
Whitfield, GA	−44.7	23.6	39,608	23
Wilcox, GA	−49.3	34.2	3,340	6
Wilkes, GA	−16.9	33.8	5,083	7
Wilkinson, GA	−17.9	42.4	4,900	9
Worth, GA	−50.5	36.8	9,291	12
Hawaii, HI	+28.9	19.7	80,911	64
Honolulu, HI	+22.0	23.7	334,790	302
Kauai, HI	+19.9	21.2	29,478	31
Maui, HI	+26.5	19.3	61,526	70
Ada, ID	−10.6	34.1	259,875	197
Adams, ID	−55.9	15.1	2,614	5
Bannock, ID	−25.9	21.6	38,635	57
Bear Lake, ID	−78.7	8.2	3,254	15
Benewah, ID	−62.8	12.8	5,029	11
Bingham, ID	−61.3	22.4	20,066	27
Blaine, ID	+32.6	27.8	12,705	16
Boise, ID	−55.6	12.5	4,792	7
Bonner, ID	−47.2	25.2	29,002	30
Bonneville, ID	−47.0	16.8	54,511	51
Boundary, ID	−67.0	14.7	6,939	7
Canyon, ID	−47.8	15.2	98,424	51
Caribou, ID	−73.4	6.6	3,351	9
Cassia, ID	−70.8	11.7	9,318	24
Clearwater, ID	−64.2	7.7	4,324	14
Custer, ID	−54.6	28.4	2,584	9
Elmore, ID	−49.8	6.5	10,402	17
Franklin, ID	−79.9	4.6	6,982	18
Fremont, ID	−71.1	12.3	6,599	13
Gem, ID	−67.3	8.8	10,406	14
Gooding, ID	−61.9	8.7	5,776	6
Idaho, ID	−69.6	10.9	9,608	28
Jefferson, ID	−75.4	5.2	15,372	21

The first 500 of 2853 rows; every row is in figures/sd_by_margin.json.

Note: The number in the tooltip is the county's number of reporting units. Kings County, New York, and the two Pennsylvania counties named in the text are labeled.

Note: The returns are full counts with no sampling error. The whiskers show how much a mean would move with a different set of counties, from a county bootstrap.

Data: vishalsingh.org/politics/report/precincts-within-counties/figures/sd_by_margin.json

Table 6. Spread rises with Democratic lean, with or without controls for county size and state

Correlation between the spread of precinct margins and the county two-party margin, Democratic positive, across 2,853 counties, 2024, with 95% intervals

Weighting	Controls	Correlation	Interval, low	Interval, high	Counties
Vote-weighted	No controls	+0.41	+0.33	+0.49	2,853
Vote-weighted	Size fixed	+0.21	+0.12	+0.30	2,853
Vote-weighted	Size and state fixed	+0.28	+0.19	+0.37	2,853
Unweighted	No controls	+0.54	+0.51	+0.56	2,853
Unweighted	Size fixed	+0.46	+0.43	+0.50	2,853
Unweighted	Size and state fixed	+0.47	+0.43	+0.51	2,853

Note: Each interval resamples counties 2,000 times; a full count has no sampling error, so the interval says how much the correlation would move with a different set of counties.

Data: vishalsingh.org/politics/report/precincts-within-counties/figures/dispersion_partials.json

Table 7. Spread falls with distance from an even split, except in vote-weighted comparisons of counties within 50 points

Correlation between the spread of precinct margins and the size of the county margin, among counties with a margin at or below each cutoff, 2024, with 95% intervals

Cutoff (points of margin)	Weighting	Counties	No controls	Size fixed	Size and state fixed
30	Vote-weighted	954	−0.02 [−0.13, +0.08]	+0.01 [−0.09, +0.10]	−0.07 [−0.18, +0.02]
30	Unweighted	954	−0.12 [−0.18, −0.06]	−0.13 [−0.19, −0.07]	−0.17 [−0.23, −0.11]
40	Vote-weighted	1,321	−0.07 [−0.18, +0.04]	−0.03 [−0.13, +0.05]	−0.08 [−0.20, 0.00]
40	Unweighted	1,321	−0.20 [−0.25, −0.14]	−0.21 [−0.26, −0.15]	−0.25 [−0.30, −0.20]
50	Vote-weighted	1,725	−0.04 [−0.18, +0.08]	+0.01 [−0.12, +0.12]	−0.04 [−0.19, +0.06]
50	Unweighted	1,725	−0.26 [−0.30, −0.22]	−0.26 [−0.30, −0.21]	−0.31 [−0.36, −0.27]
60	Vote-weighted	2,156	−0.15 [−0.26, −0.04]	−0.08 [−0.18, +0.03]	−0.11 [−0.24, −0.02]
60	Unweighted	2,156	−0.38 [−0.41, −0.34]	−0.36 [−0.39, −0.32]	−0.39 [−0.44, −0.35]
70	Vote-weighted	2,593	−0.24 [−0.34, −0.13]	−0.15 [−0.25, −0.04]	−0.20 [−0.33, −0.10]
70	Unweighted	2,593	−0.48 [−0.51, −0.45]	−0.44 [−0.47, −0.40]	−0.48 [−0.52, −0.45]
100	Vote-weighted	2,853	−0.29 [−0.39, −0.20]	−0.19 [−0.30, −0.09]	−0.25 [−0.37, −0.16]
100	Unweighted	2,853	−0.55 [−0.57, −0.52]	−0.49 [−0.52, −0.46]	−0.55 [−0.58, −0.52]

Note: The last cutoff, 100 points, includes every county, because no margin can be larger. The number in the tooltip is the number of counties in the row. Each interval resamples the counties of the row 2,000 times; a full count has no sampling error, so the interval says how much the correlation would move with a different set of counties.

Data: vishalsingh.org/politics/report/precincts-within-counties/figures/ext_by_cutoff.json

Table 8. Near-tied counties differ widely in how much their precinct margins vary

Share of the near-tied counties in each 5-point bin of spread of precinct margins, 2024; margin under 5 points and at least 20 precincts

n	share	x0	x1
11	9.91	10	15
21	18.92	15	20
34	30.63	20	25
16	14.41	25	30
11	9.91	30	35
11	9.91	35	40
5	4.50	40	45
1	0.901	45	50
0	0	50	55
1	0.901	55	60

Note: The number in the tooltip is the number of counties in the bin.

Note: Full counts of votes: there is no sampling, so the shares carry no confidence interval.

Data: vishalsingh.org/politics/report/precincts-within-counties/figures/near_tied_sd.json

Table 9. Dropping ballot-bucket units moves each correlation by at most 0.02 and each vote share by at most 0.3 points

Main statistics in the full sample and in a side check that drops ballot-bucket units, 2024 two-party presidential returns

Statistic	Full sample	Without ballot-bucket units
Counties with a spread	2,853	2,721
Near-tied counties	111	106
Median spread of near-tied counties (points)	23.9	24.0
Correlation of spread with Democratic lean	+0.41	+0.40
Same, with county size and state fixed	+0.28	+0.27
Correlation of spread with distance from an even split, counties within 50 points	−0.04	−0.04
Votes in precincts decided by 20 points or more	65.0%	64.8%
Votes in precincts decided by under 10 points	18.5%	18.6%

Note: The changes in the title are the largest differences before rounding, rounded up to the decimals printed.

Data: vishalsingh.org/politics/report/precincts-within-counties/figures/side_check.json

All estimates

Every fact in facts.json (160), sorted by id. The same values as JSON: facts.json.

Fact id	Value	Unit	Estimand	Population	Period	Interval	n	Weights	Source	Note
alaska_share_cert	0.2%	percent of the certified two-party votes	share of certified two-party votes cast in Alaska	all counties with returns	2024 presidential general election			none (full counts)	County election returns
all_median_votes	13,707	two-party votes	median county size	counties in the analysis sample with at least 5 reporting units	2024 presidential general election		2,853	none (full counts); each county counted once	Precinct presidential returns
beyond_max_sd	34.7	points of two-party margin	largest county spread	counties with a margin larger than 70 points	2024 presidential general election			none (full counts)	Precinct presidential returns
beyond_n	260	counties	count of counties with a margin larger than 70 points	counties in the analysis sample with at least 5 reporting units	2024 presidential general election			none (full counts)	Precinct presidential returns
beyond_ratio_max	49%	percent of the limit	largest ratio of a county's spread to the largest spread its margin allows	counties with a margin larger than 70 points	2024 presidential general election			none (full counts)	Precinct presidential returns
beyond_ratio_mean	12%	percent of the limit	mean ratio of a county's spread to the largest spread its margin allows	counties with a margin larger than 70 points	2024 presidential general election		260	none (full counts); each county counted once	Precinct presidential returns
bin_blue_end	19.3	points of two-party margin	mean county spread weighted by votes	counties in the analysis sample in a 10-point bin of county margin (at least 10 counties)	2024 presidential general election	95% CI 15.3 to 23.9	12	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
bin_blue_end_n	12	counties	count	counties in that bin	2024 presidential general election			none (full counts)	Precinct presidential returns
bin_blue_end_x	66	points of two-party margin	vote-weighted mean county margin	counties in the analysis sample in that bin	2024 presidential general election		12	none (full counts); counties weighted by their two-party votes	Precinct presidential returns
bin_diff_gap	6.9	points of two-party margin	difference between the vote-weighted mean spreads of the highest bin and that bin	counties in the highest bin and in that bin	2024 presidential general election	95% CI 0.7 to 12.9	203	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from resampling the counties of each bin separately (2,000 replicates, seed 12345).
bin_diff_x	4	points of two-party margin	vote-weighted mean county margin (Republican lead)	counties in that bin	2024 presidential general election		169	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	The one bin of the run, other than the highest bin, whose difference from the highest bin has a 95% interval that excludes zero.
bin_gap_blue	11.8	points of two-party margin	difference between the vote-weighted mean spreads of the two bins	counties in the highest bin and in the bluest bin	2024 presidential general election	95% CI 3.9 to 18.9	46	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from resampling the counties of each bin separately (2,000 replicates, seed 12345).
bin_peak	31.1	points of two-party margin	mean county spread weighted by votes	counties in the analysis sample in a 10-point bin of county margin (at least 10 counties)	2024 presidential general election	95% CI 24.7 to 36.8	34	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
bin_peak_x	43	points of two-party margin	vote-weighted mean county margin	counties in the analysis sample in that bin	2024 presidential general election		34	none (full counts); counties weighted by their two-party votes	Precinct presidential returns
bin_plat_end_x	34	points of two-party margin	vote-weighted mean county margin (Democratic lead)	counties in that bin	2024 presidential general election		50	none (full counts); counties weighted by their two-party votes	Precinct presidential returns
bin_plat_max	28.4	points of two-party margin	largest binned mean among those bins	counties in the analysis sample in a 10-point bin of county margin (at least 10 counties)	2024 presidential general election			none (full counts); counties weighted by their two-party votes	Precinct presidential returns
bin_plat_min	24.1	points of two-party margin	smallest binned mean among those bins	counties in the analysis sample in a 10-point bin of county margin (at least 10 counties)	2024 presidential general election			none (full counts); counties weighted by their two-party votes	Precinct presidential returns
bin_plat_n	6	bins	count	bins whose intervals overlap the interval of the highest bin, counted back from it, other than the highest bin	2024 presidential general election			none (full counts)	Precinct presidential returns
bin_plat_start	25.4	points of two-party margin	mean county spread weighted by votes	counties in the analysis sample in a 10-point bin of county margin (at least 10 counties)	2024 presidential general election	95% CI 23.4 to 27.5	201	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
bin_plat_start_x	14	points of two-party margin	vote-weighted mean county margin (Republican lead)	counties in that bin	2024 presidential general election		201	none (full counts); counties weighted by their two-party votes	Precinct presidential returns
bin_red_end	6.7	points of two-party margin	mean county spread weighted by votes	counties in the analysis sample in a 10-point bin of county margin (at least 10 counties)	2024 presidential general election	95% CI 5.2 to 8.0	40	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
bin_red_end_x	82	points of two-party margin	vote-weighted mean county margin	counties in the analysis sample in that bin	2024 presidential general election		40	none (full counts); counties weighted by their two-party votes	Precinct presidential returns
bin_width	10	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	Width of the margin bins used for the binned means and the precinct histograms.
bound_at_cut	71.4	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	Precinct margins lie between -100 and 100, so a county with margin M cannot have a spread above the square root of 100 squared minus M squared; this is the limit for a margin of 70 points.
bucks_comp	50.0%	percent of the county's two-party votes	share of votes cast in precincts decided by under 10 points	Bucks County, PA	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
bucks_margin	−0.1	points of two-party margin	two-party margin, Democratic positive	Bucks County, PA	2024 presidential general election			none (full counts)	Precinct presidential returns
bucks_max_d	42.0	points of two-party margin	margin of the most Democratic precinct	Bucks County, PA	2024 presidential general election			none (full counts)	Precinct presidential returns
bucks_max_r	33.7	points of two-party margin	margin of the most Republican precinct, as a Republican lead	Bucks County, PA	2024 presidential general election			none (full counts)	Precinct presidential returns
bucks_sd	14.8	points of two-party margin	vote-weighted standard deviation of precinct margins	Bucks County, PA	2024 presidential general election		304	none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
bucks_units	304	precincts	count	Bucks County, PA	2024 presidential general election			none (full counts)	Precinct presidential returns
centre_comp	5.5%	percent of the county's two-party votes	share of votes cast in precincts decided by under 10 points	Centre County, PA	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
centre_margin	+2.9	points of two-party margin	two-party margin, Democratic positive	Centre County, PA	2024 presidential general election			none (full counts)	Precinct presidential returns
centre_max_d	65.0	points of two-party margin	margin of the most Democratic precinct	Centre County, PA	2024 presidential general election			none (full counts)	Precinct presidential returns
centre_max_r	75.2	points of two-party margin	margin of the most Republican precinct, as a Republican lead	Centre County, PA	2024 presidential general election			none (full counts)	Precinct presidential returns
centre_sd	36.3	points of two-party margin	vote-weighted standard deviation of precinct margins	Centre County, PA	2024 presidential general election		87	none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
centre_units	87	precincts	count	Centre County, PA	2024 presidential general election			none (full counts)	Precinct presidential returns
comp_equiv	55%	percent of the two-party vote	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A margin of 10 points is a 55 to 45 split of the two-party vote.
cut_beyond	70	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	Counties with a margin larger than this are the tails of the distribution.
cut_big_votes	100,000	two-party votes	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	Counties with at least this many two-party votes are called large.
cut_comp	10	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A place is called close when its two-party margin is smaller than this.
cut_deep	40	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A place is called very lopsided when its two-party margin is this large or larger.
cut_floor_units	5	reporting units	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A county needs at least this many reporting units for a spread estimate.
cut_land	20	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A place is called a landslide when its two-party margin is this large or larger.
cut_mid_lo	15	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	Lower end of the middle range of near-tied spreads: a spread of this many points or more and under the wide-spread cutoff.
cut_near	5	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A county is near-tied when its two-party margin is smaller than this.
cut_near_units	20	precincts	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A near-tied county needs at least this many precincts.
cut_nongeo_share	20%	percent of the county's votes	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	Counties in which ballot-bucket units (absentee, provisional, early voting and the like) hold this share of votes or more are left out of the side check.
cut_sd	30	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A county spread of 30 points is called wide.
cut_sd_top	50	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A county is called one of the widest-spread counties when its spread is this many points or more.
cut_small_units	10	reporting units	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A county with fewer reporting units than this is called small in the note on the map.
cut_two_share	20%	percent of the county's votes	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	Share of a county's votes in landslide precincts of one party for the two-landslide test.
cut_within	50	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	Counties with a margin of this many points or less (a margin of exactly this size included) are used for the check that leaves out the tails.
cutoff_30	30	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A cutoff of the county margin in the check of how the distance correlation depends on the cutoff (counties with a margin of this many points or less).
cutoff_40	40	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A cutoff of the county margin in the check of how the distance correlation depends on the cutoff (counties with a margin of this many points or less).
cutoff_60	60	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A cutoff of the county margin in the check of how the distance correlation depends on the cutoff (counties with a margin of this many points or less).
floor_vw_mean	3.1	points of two-party margin	mean of the spread expected if voters were assigned to precincts at random, weighted by votes	counties in the analysis sample with at least 5 reporting units	2024 presidential general election		2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns
la_share	51.5%	percent of the certified two-party votes	ratio of precinct votes to certified votes	Louisiana parishes	2024 presidential general election			none (full counts)	Precinct presidential returns
land_equiv	60%	percent of the two-party vote	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A margin of 20 points is a 60 to 40 split of the two-party vote.
margin_arlington	+59.9	points of two-party margin	two-party margin, Democratic positive	Arlington (a county with at least 100,000 two-party votes)	2024 presidential general election			none (full counts)	Precinct presidential returns
margin_dc	+86.6	points of two-party margin	two-party margin, Democratic positive	District of Columbia (a county with at least 100,000 two-party votes)	2024 presidential general election			none (full counts)	Precinct presidential returns
margin_max	100	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	The largest possible two-party margin, in points.
margin_metro1	+11.7	points of two-party margin	vote-weighted mean county margin	metro counties of 1 million or more in the analysis sample	2024 presidential general election	95% CI 7.3 to 15.7	419	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
margin_open	−45.2	points of two-party margin	vote-weighted mean county margin	the least urban nonmetro counties in the analysis sample	2024 presidential general election	95% CI −47.6 to −42.7	873	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
min_bin_counties	10	counties	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A bin of county margin is shown only when it holds at least this many counties.
n_acs	2,843	counties	count	counties in the analysis sample with at least 5 reporting units and ACS measures	2024 presidential general election			none (full counts)	County demographics panel
n_below_floor	190	counties	count	counties in the analysis sample	2024 presidential general election			none (full counts)	Precinct presidential returns	Counties with fewer than 5 reporting units have no spread estimate.
n_big	318	counties	count	counties in the analysis sample with at least 5 reporting units	2024 presidential general election			none (full counts)	Precinct presidential returns
n_boot	2,000	resamples	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	Number of county resamples behind each interval.
n_counties	3,043	counties	count	counties in the analysis sample	2024 presidential general election			none (full counts)	Precinct presidential returns
n_counties_disp	2,853	counties	count	counties in the analysis sample with at least 5 reporting units	2024 presidential general election			none (full counts)	Precinct presidential returns
n_no_rucc	10	counties	count of counties with no Rural-Urban Continuum Code in the panel	counties in the analysis sample with at least 5 reporting units	2024 presidential general election			none (full counts)	County demographics panel	The Connecticut counties (the panel uses the 2022 planning regions), Kansas City, Missouri, and Oglala Lakota County, South Dakota.
n_out_la	64	parishes	count	Louisiana parishes	2024 presidential general election			none (full counts)	Precinct presidential returns
n_out_other	6	counties	count	counties outside Louisiana whose precinct rows do not add to the certified total	2024 presidential general election			none (full counts)	Precinct presidential returns
n_out_total	70	counties	count	counties whose precinct rows do not add to the certified total (Louisiana and others)	2024 presidential general election			none (full counts)	Precinct presidential returns
n_sd30	368	counties	count	counties in the analysis sample with at least 5 reporting units	2024 presidential general election			none (full counts)	Precinct presidential returns
n_sd_top	33	counties	count of counties with a spread of 50 points or more	counties in the analysis sample with at least 5 reporting units	2024 presidential general election			none (full counts)	Precinct presidential returns
n_sd_top_msal	20	counties	count of those counties in Mississippi or Alabama	counties in the analysis sample with a spread of 50 points or more	2024 presidential general election			none (full counts)	Precinct presidential returns
n_sd_top_small	4	counties	count of those counties with fewer than 10 reporting units	counties in the analysis sample with a spread of 50 points or more	2024 presidential general election			none (full counts)	Precinct presidential returns
n_sim	200	simulated assignments	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	Number of simulated assignments of voters to precincts behind the random-assignment bars.
n_states	48	states	count	states in the analysis sample, not counting the District of Columbia	2024 presidential general election			none (full counts)	Precinct presidential returns
n_units	175,345	reporting units	count	reporting units (precincts) in the analysis sample	2024 presidential general election			none (full counts)	Precinct presidential returns
n_within50	1,725	counties	count	counties in the analysis sample with at least 5 reporting units and a margin of 50 points or less	2024 presidential general election			none (full counts)	Precinct presidential returns
near_floor	3.4	points of two-party margin	median of the spread expected if voters were assigned to precincts at random	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election		111	none (full counts); each county counted once	Precinct presidential returns
near_max_sd	58.1	points of two-party margin	largest county spread	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts)	Precinct presidential returns
near_median_sd	23.9	points of two-party margin	median of county spreads	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election	95% CI 22.8 to 24.9	111	none (full counts); each county counted once	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
near_median_votes	78,269	two-party votes	median county size	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election		111	none (full counts); each county counted once	Precinct presidential returns
near_min_sd	10.1	points of two-party margin	smallest county spread	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts)	Precinct presidential returns
near_n	111	counties	count	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts)	Precinct presidential returns
near_n_sd30	29	counties	count with a spread of 30 or more	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts)	Precinct presidential returns
near_n_two	39	counties	count with one fifth or more of the votes in Democratic landslide precincts and one fifth or more in Republican landslide precincts	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts)	Precinct presidential returns
near_share_comp	35.6%	percent of the two-party votes of these counties	share of votes cast in precincts in the band	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
near_share_deep	10.5%	percent of the two-party votes of these counties	share of votes cast in precincts in the band	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
near_share_land	38.2%	percent of the two-party votes of these counties	share of votes cast in precincts in the band	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
near_share_land_d	17.5%	percent of the two-party votes of these counties	share of votes cast in precincts in the band	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
near_share_land_r	20.7%	percent of the two-party votes of these counties	share of votes cast in precincts in the band	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
near_share_mid	64.0%	percent of counties	share with a spread of 15 points or more and under 30	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts); each county counted once	Precinct presidential returns
near_share_sd30	26.1%	percent of counties	share with a spread of 30 or more	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts); each county counted once	Precinct presidential returns
near_share_two	35.1%	percent of counties	share of counties in the previous count	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts); each county counted once	Precinct presidential returns
near_votes	18.9 million	two-party votes	sum	near-tied counties in the analysis sample: two-party margin within 5 points and at least 20 precincts	2024 presidential general election			none (full counts)	Precinct presidential returns
nongeo_share	1.5%	percent of two-party votes	share of votes in units labelled as ballot buckets: absentee, provisional, early voting, mail, failsafe, military, overseas and statistical-adjustment	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
nongeo_units	870	reporting units	count	reporting units (precincts) in the analysis sample	2024 presidential general election			none (full counts)	Precinct presidential returns
out_share_cert	2.0%	percent of the certified two-party votes	share	all counties with returns	2024 presidential general election			none (full counts)	County election returns	The 70 counties left out by the reconciliation rule; Alaska is a further share.
r_cut60	−0.15	correlation coefficient	correlation of distance from an even split with county spread	counties in the analysis sample with at least 5 reporting units and a margin of 60 points or less	2024 presidential general election	95% CI −0.26 to −0.04	2,156	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_cutallu	−0.55	correlation coefficient	correlation of distance from an even split with county spread, each county counted once	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI −0.57 to −0.52	2,853	none (full counts); each county counted once	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_ext50_raw	−0.04	correlation coefficient	correlation of distance from an even split with county spread	counties in the analysis sample with at least 5 reporting units and a margin of 50 points or less	2024 presidential general election	95% CI −0.18 to 0.08	1,725	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_ext50u_raw	−0.26	correlation coefficient	correlation of distance from an even split with county spread, each county counted once	counties in the analysis sample with at least 5 reporting units and a margin of 50 points or less	2024 presidential general election	95% CI −0.30 to −0.22	1,725	none (full counts); each county counted once	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_ext_fe	−0.25	correlation coefficient	correlation of distance from an even split with county spread after size and state controls	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI −0.37 to −0.16	2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_ext_raw	−0.29	correlation coefficient	correlation of the county margin's distance from zero with county spread	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI −0.39 to −0.20	2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_ext_size	−0.19	correlation coefficient	correlation of distance from an even split with county spread after removing size	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI −0.30 to −0.09	2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_lean50_raw	+0.41	correlation coefficient	correlation of county margin with county spread	counties in the analysis sample with at least 5 reporting units and a margin of 50 points or less	2024 presidential general election	95% CI 0.32 to 0.49	1,725	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_lean_fe	+0.28	correlation coefficient	correlation of county margin with county spread after removing the linear effects of log votes and log precincts and state means	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI 0.19 to 0.37	2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_lean_logvotes	+0.64	correlation coefficient	correlation of county margin with the log of two-party votes	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI 0.59 to 0.69	2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_lean_raw	+0.41	correlation coefficient	correlation of county margin with county spread	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI 0.33 to 0.49	2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_lean_size	+0.21	correlation coefficient	correlation of county margin with county spread after removing linear effects of log votes and log precincts	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI 0.12 to 0.30	2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_lean_unw	+0.54	correlation coefficient	correlation of county margin with county spread, each county counted once	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI 0.51 to 0.56	2,853	none (full counts); each county counted once	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_lean_unw_fe	+0.47	correlation coefficient	correlation of county margin with county spread after size and state controls, each county counted once	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI 0.43 to 0.51	2,853	none (full counts); each county counted once	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_nonwhite_fe	+0.31	correlation coefficient	correlation of the nonwhite share with county spread after size and state controls	counties in the analysis sample with at least 5 reporting units and ACS measures	2024 presidential general election	95% CI 0.22 to 0.40	2,843	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_nonwhite_raw	+0.43	correlation coefficient	correlation of the nonwhite share (ACS 2024) with county spread	counties in the analysis sample with at least 5 reporting units and ACS measures	2024 presidential general election	95% CI 0.36 to 0.50	2,843	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_rural_fe	−0.13	correlation coefficient	correlation of the rural share with county spread after size and state controls	counties in the analysis sample with at least 5 reporting units and ACS measures	2024 presidential general election	95% CI −0.19 to −0.08	2,843	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_rural_raw	−0.36	correlation coefficient	correlation of the rural share (2020 census urban area definition, county panel) with county spread	counties in the analysis sample with at least 5 reporting units and ACS measures	2024 presidential general election	95% CI −0.41 to −0.30	2,843	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
r_sd_logvotes	+0.40	correlation coefficient	correlation of county spread with the log of two-party votes	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI 0.33 to 0.46	2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
rb_dcorr_max	0.02	correlation coefficient	largest absolute change, rounded up to two decimals, across the correlations of spread with lean (raw and with size and state fixed) and with distance from an even split within 50 points	counties in the side check and in the full sample	2024 presidential general election			none (full counts); counties weighted by their two-party votes	Precinct presidential returns
rb_dshare_max	0.3	percentage points of votes	largest absolute change, rounded up to one decimal, across the shares of votes in precincts decided by 20 points or more and by under 10 points	units in the side check and in the full sample	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
rb_n_counties	2,721	counties	count	counties in the side check	2024 presidential general election			none (full counts)	Precinct presidential returns
rb_near_n	106	counties	count	near-tied counties in the side check	2024 presidential general election			none (full counts)	Precinct presidential returns
sd_al	32.2	points of two-party margin	mean of county spreads weighted by votes	Alabama counties with at least 5 reporting units	2024 presidential general election	95% CI 25.2 to 38.3	67	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345), resampling the counties of the state.
sd_arlington	6.5	points of two-party margin	vote-weighted standard deviation of precinct margins	Arlington (a county with at least 100,000 two-party votes)	2024 presidential general election		55	none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
sd_bin_width	5	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	Width of the spread bins in the histogram of near-tied counties.
sd_dc	5.9	points of two-party margin	vote-weighted standard deviation of precinct margins	District of Columbia (a county with at least 100,000 two-party votes)	2024 presidential general election		144	none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
sd_equiv	15	points of Democratic vote share	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	A spread of 30 margin points is a spread of 15 points of the Democratic share of the two-party vote.
sd_jeffal	53.5	points of two-party margin	vote-weighted standard deviation of precinct margins	Jefferson County, AL, 2024 (a county with at least 100,000 two-party votes)	2024 presidential general election		179	none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
sd_kings	54.9	points of two-party margin	vote-weighted standard deviation of precinct margins	Kings County, NY, 2024 (a county with at least 100,000 two-party votes)	2024 presidential general election		1,341	none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
sd_median	15.6	points of two-party margin	median of county spreads	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI 15.0 to 16.0	2,853	none (full counts); each county counted once	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
sd_metro1	24.8	points of two-party margin	mean of county spreads weighted by two-party votes	counties in the analysis sample with at least 5 reporting units, metro area of 1 million or more (Rural-Urban Continuum Code 1, 2023)	2024 presidential general election	95% CI 23.5 to 26.1	419	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
sd_metro2	22.7	points of two-party margin	mean of county spreads weighted by two-party votes	counties in the analysis sample with at least 5 reporting units, smaller metro area (Rural-Urban Continuum Code 2 to 3, 2023)	2024 presidential general election	95% CI 21.9 to 23.5	690	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
sd_mobile	50.2	points of two-party margin	vote-weighted standard deviation of precinct margins	Mobile County, AL, 2024 (a county with at least 100,000 two-party votes)	2024 presidential general election		82	none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
sd_ms	38.2	points of two-party margin	mean of county spreads weighted by votes	Mississippi counties with at least 5 reporting units	2024 presidential general election	95% CI 34.9 to 41.5	82	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345), resampling the counties of the state.
sd_open	15.5	points of two-party margin	mean of county spreads weighted by two-party votes	counties in the analysis sample with at least 5 reporting units, nonmetro, smaller towns and open country (Rural-Urban Continuum Code 8 to 9, 2023)	2024 presidential general election	95% CI 14.6 to 16.5	873	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
sd_town	19.4	points of two-party margin	mean of county spreads weighted by two-party votes	counties in the analysis sample with at least 5 reporting units, nonmetro, larger towns (Rural-Urban Continuum Code 4 to 7, 2023)	2024 presidential general election	95% CI 18.7 to 20.1	861	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
sd_vw_mean	23.3	points of two-party margin	mean of county spreads weighted by two-party votes	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI 22.5 to 24.1	2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
share_comp_county	23.1%	percent of two-party votes	share of votes cast in counties in the band	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
share_comp_precinct	18.5%	percent of two-party votes	share of votes cast in precincts in the band	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
share_comp_random	23.3%	percent of two-party votes	mean over 200 simulated assignments of the share of votes in precincts in the band, when each precinct's Democratic votes are a binomial draw of its votes at its county's Democratic share	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election		200	none; simulation with unit sizes and county margins held fixed (seed 12345)	Precinct presidential returns
share_deep_county	25.4%	percent of two-party votes	share of votes cast in counties in the band	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
share_deep_precinct	36.4%	percent of two-party votes	share of votes cast in precincts in the band	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
share_deep_random	25.0%	percent of two-party votes	mean over 200 simulated assignments of the share of votes in precincts in the band, when each precinct's Democratic votes are a binomial draw of its votes at its county's Democratic share	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election		200	none; simulation with unit sizes and county margins held fixed (seed 12345)	Precinct presidential returns
share_land_county	57.2%	percent of two-party votes	share of votes cast in counties in the band	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
share_land_precinct	65.0%	percent of two-party votes	share of votes cast in precincts in the band	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
share_land_random	56.6%	percent of two-party votes	mean over 200 simulated assignments of the share of votes in precincts in the band, when each precinct's Democratic votes are a binomial draw of its votes at its county's Democratic share	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election		200	none; simulation with unit sizes and county margins held fixed (seed 12345)	Precinct presidential returns
sim_county_gap	0.7	percentage points of votes	largest absolute difference across the three bands between the random-assignment share and the county share	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election			none (full counts); precinct results weighted by their two-party votes	Precinct presidential returns
sim_range	0.4	percentage points of votes	largest difference between the highest and lowest of the simulated shares, across the three bands	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election		200	none; simulation (seed 12345)	Precinct presidential returns
slope_fe	0.9	points of spread per 10 points of margin	weighted least squares slope of county spread on county margin, times 10, with log votes, log precincts and state means	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI 0.6 to 1.3	2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
slope_raw	1.1	points of spread per 10 points of margin	weighted least squares slope of county spread on county margin, times 10	counties in the analysis sample with at least 5 reporting units	2024 presidential general election	95% CI 0.8 to 1.4	2,853	none (full counts); counties weighted by their two-party votes	Precinct presidential returns	95% interval from a county bootstrap (2,000 replicates, seed 12345).
slope_step	10	points of two-party margin	definition	definition used in this chapter	2024 presidential general election			none (definition)	Precinct presidential returns	Step in county margin for the slope of spread on margin.
unit_ca_per_county	578	precincts per county	mean count of reporting units per county	California counties in the analysis sample	2024 presidential general election			none (full counts)	Precinct presidential returns
unit_med_max	2,083	two-party votes per precinct	median precinct size	Connecticut precincts in the analysis sample	2024 presidential general election		756	none (full counts)	Precinct presidential returns
unit_med_min	227	two-party votes per precinct	median precinct size	Kansas precincts in the analysis sample	2024 presidential general election		3,737	none (full counts)	Precinct presidential returns
unit_nd_per_county	7	precincts per county	mean count of reporting units per county	North Dakota counties in the analysis sample	2024 presidential general election			none (full counts)	Precinct presidential returns
votes_sample	149.0 million	two-party votes	sum of Democratic and Republican votes	two-party presidential votes in the analysis sample (counties whose precinct rows match the certified total; Alaska left out)	2024 presidential general election			none (full counts)	Precinct presidential returns
votes_sd30	18.7%	percent of two-party votes	share of the votes of these counties cast in counties with a spread of 30 or more	counties in the analysis sample with at least 5 reporting units	2024 presidential general election			none (full counts); counties weighted by their two-party votes	Precinct presidential returns

Definitions

Precinct: The smallest area for which election officials report votes, usually the voters assigned to one polling place. Precinct boundaries change between elections, so the same precinct cannot be followed over time.
Standard deviation: A measure of how far values typically fall from their average. A larger standard deviation means the values are more spread out.
County two-party margin: The Democratic vote minus the Republican vote, divided by the sum of the two, so a positive value is a Democratic lead. Votes for other candidates are left out.
Percentage point: The unit for the difference between two percentages. A change from one share to another is stated in points, not in percent, so that absolute and relative change are not confused.
Rural-Urban Continuum Code: A USDA scheme that sorts counties into nine classes, from large metropolitan areas to remote rural ones, by population size and nearness to a metropolitan area. The 2013 and 2023 editions classify some counties differently.
Correlation: A number from minus 1 to plus 1 for how closely two measures move together in a straight-line pattern. Zero means no straight-line pattern; a correlation does not say that one measure causes the other.
Fixed effects: Regression terms that give each group, such as each country or each year, its own baseline. The other coefficients then compare respondents within the same group.
Ecological inference: Drawing a conclusion about individuals from data on groups or places, such as counties. A pattern across counties can differ from the pattern among the people who live in them.

Methods

Sample: the 2024 presidential returns in the MIT Election Data and Science Lab precinct file, two-party votes per reporting unit (Democratic: Harris; Republican: Trump; write-ins and other candidates left out) from b3.load.precinct_two_party, which takes a precinct's TOTAL row where the state reports one and otherwise adds the rows for each voting mode. A 'precinct' is the unit the state or county election office reports, so it varies in size and kind by state. Rules applied in order: units with no two-party vote or a negative count are dropped (15,602 units, three of them Michigan statistical adjustments); Alaska is dropped (523 units; its 2024 county codes are election districts); 4 units with no county code are dropped; 123 Kansas City units are moved from code 36000 to 2938000, the code of the county file; a county is kept only when its precinct rows add to between 95% and 105% of its certified two-party vote in the repaired county file, which removes 70 counties (64 Louisiana parishes, where the precinct rows hold about 52% of the certified vote, and 6 others, four of them with rows that appear twice, in Bergen and Gloucester, NJ, and Hendricks and St. Joseph, IN). The analysis sample is 175,345 units, 148,953,406 two-party votes and 3,043 counties in 48 states and the District of Columbia; the 70 excluded counties hold 2.0% of the certified votes and Alaska a further 0.2%. Estimands: a precinct or county margin is 100 times the Democratic minus the Republican votes over their sum; the spread of a county is the standard deviation of its precinct margins about the county margin, weighted by each precinct's two-party votes (population divisor), and needs at least 5 reporting units; the spread expected from chance is 200 times the square root of p(1 - p) times the number of units over the votes, with p the Democratic two-party share, which is the spread if each voter were assigned to a unit at random. Near-tied counties have a margin below 5 points in absolute value and at least 20 precincts. Shares of votes in bands use exact tests on vote counts (a margin of 20 points or more is 5 |D - R| >= D + R). Random-assignment benchmark for the shares in bands: 200 simulated assignments (seed 12345) in which each precinct keeps its two-party votes and its county's Democratic share and its Democratic votes are a binomial draw; the figure shows the mean of the runs, and the largest range of a share across runs is 0.4 points. County correlations are weighted by two-party votes unless the text says each county is counted once; holding county size fixed removes the linear effect of the log of two-party votes and the log of the number of units, and holding state fixed removes each state's weighted mean from every variable (equal to a regression with state dummies). The slope of spread on margin is the coefficient of a weighted regression with the same controls, per 10 points of margin. Counties within 50 points have a margin of 50 points or less in absolute value; the correlation of spread with distance from an even split is also computed at cutoffs of 30, 40, 60 and 70 points and across all counties, weighted and counting each county once, each with no controls, with county size fixed and with size and state fixed; the correlation of spread with lean is computed weighted and counting each county once, with the same three sets of controls. Binned means use 10-point bins of county margin and need 10 counties. Place types use the USDA Rural-Urban Continuum Code, 2023 edition (1; 2 and 3; 4 to 7; 8 and 9); nonwhite share is 100 minus the non-Hispanic white share (ACS 2024) and rural share is the share of residents outside 2020 census urban areas, both from the county demographics panel, which has no values for the Connecticut counties, Kansas City, Missouri, and Oglala Lakota County, South Dakota. Weights: none from a survey, because the returns are full counts; statistics are weighted by two-party votes as stated. Intervals: the returns have no sampling error, so shares, counts and county spreads carry no interval; a correlation, a slope, a mean or a median across a set of counties has a 95% percentile interval from a county bootstrap (2,000 replicates, seed 12345); the interval for the difference between two bins of county margin resamples the counties of each bin separately, and a state mean resamples the counties of the state. Side check: dropping the units labelled as absentee, provisional, early voting, mail, failsafe, military, overseas and statistical-adjustment units (870 units, found by these words in the label: absen(tee), abs, provisional, prov, early voting, early vote, earlyvote, early on its own, EV, mail, statistical adjustments, military, overseas, failsafe) and the counties where they hold 20% of the votes or more leaves 2,721 counties with a spread; the results are printed beside the full-sample values in the section on what the data cannot show. Suppression: no county with fewer than 5 reporting units enters a spread statistic; no other cell is suppressed. Everything is a 2024 cross-section.

What these data cannot show

The chapter describes one election.
It says nothing about whether precinct margins are spreading or narrowing, and it makes no comparison with earlier years.
Planned, Sorting by geographic scale, 2016 to 2024 (https://vishalsingh.org/politics/sorting-by-geographic-scale; planned), a planned chapter, will compare precincts across elections, and Chapter 6.1, Nationalization of the county vote (https://vishalsingh.org/politics/nationalization-of-the-county-vote) measures how closely county results move together from one election to the next.
A precinct is a reporting unit and not a neighborhood.
The file has no boundaries, so the data cannot say which precincts are adjacent, and a county with a wide spread need not have opposed precincts next to each other.
Units also differ in kind.
Units labelled absentee, provisional, early voting, mail, failsafe, military or overseas, and units labelled as statistical adjustments, hold 1.5% of votes across 870 units, and they are buckets of ballots and not places.
Table 9 repeats the main statistics without them and without the counties where they hold 20% of votes or more.
That leaves 2,721 counties with a spread and 106 near-tied counties, against 111 in the full sample.
Table 9.
Dropping ballot-bucket units moves each correlation by at most 0.02 and each vote share by at most 0.3 points
A precinct margin describes a place and not the voters in it.
A precinct that gave one party 60% or more still holds voters of the other.
Ecological inference, which moves from places to individuals, can fail, because a pattern across places can differ from the pattern among individuals [5].
The results also depend on the units.
Shares and spreads change with the size and shape of the areas, a problem known as the modifiable areal unit problem [6], and this chapter uses the units that election offices happened to report.
The 64 Louisiana parishes, the 6 other counties and Alaska that are left out are not a random set.
The cutoffs for near-tied counties and for a wide spread are choices, and so are the vote weights and the 50-point cutoff behind the correlation of spread with distance from an even split.
That correlation is near zero only in the vote-weighted comparisons within 50 points or less.
A single spread cannot tell a county with two humps from a county with a long tail.
The random-assignment benchmark holds each unit's size and its county's margin fixed and does not model why voters differ across precincts.
Nothing here identifies why spread is wider in some counties.
It goes with lean, size, nonwhite share and place type, and the controls are few and linear.

References

Bishop, Bill; Cushing, Robert G. (2008). The Big Sort: Why the Clustering of Like-Minded America Is Tearing Us Apart. Houghton Mifflin.
Abrams, Samuel J.; Fiorina, Morris P. (2012). "The Big Sort" That Wasn't: A Skeptical Reexamination. PS: Political Science and Politics 45(2): 203-210. doi:10.1017/S1049096512000017
Brown, Jacob R.; Enos, Ryan D. (2021). The Measurement of Partisan Sorting for 180 Million Voters. Nature Human Behaviour 5: 998-1008. doi:10.1038/s41562-021-01066-z
Rodden, Jonathan A. (2019). Why Cities Lose: The Deep Roots of the Urban-Rural Political Divide. Basic Books.
Robinson, W. S. (1950). Ecological Correlations and the Behavior of Individuals. American Sociological Review 15(3): 351-357.
Openshaw, Stan (1984). The Modifiable Areal Unit Problem. Concepts and Techniques in Modern Geography 38, Norwich: Geo Books.

Provenance

Pipeline version: 1.0.0
Build script: book3/chapters/precincts-within-counties/build.py (sha256 6ee74aa11054b92466524b4220c8cb6f1c7b699f116c5ba88fdf1807d0399232)
Built on: 2026-09-30
Site commit: 16414b2c7257546a7042d0b1734657f208999f60

Inputs

File	Size (bytes)	SHA-256, first 1 MB	SHA-256, last 1 MB
data/county/pres_county_1868_2024.parquet	6,295,675	bec11c7a0cb5d4180bbd6809d048bc892dd00dfcdde527fa4da871b1dd3f835f	b2a4f000f2eea72d09af8939555289e924875cca40cd95ec8869104cd575bed7
data/county/pres_county_2000_2024.parquet	5,622,625	89e55d8bb32746282a8a0880a7d0e82892acf449eaea71ac1aa7466cc9b0cc23	d6c6a14fdff6f54e9ee88e46c71dce64ee40b940e050f92d18540e4889f4a0f3
data/precinct/pres_precinct_2016_2020_2024.parquet	12,200,115	53917fd567a1a7267fb02b7f7c0f229d3b251f32be472968a3fd4577653b4956	7868d4ba4664ffc59db2f5966b3f8812b455b6ab9d8bd52781768a925552efd3

Outputs

File	SHA-256
facts.json	b70068b8a5df4f5b567913a6a808faccbb78c09e76ae98eaa0eed42710d9917c
figures/county_sd_map.json	580882435f9a85273f55857706f49cf5508aae9e94b6e74cee02c2e019b63f26
figures/dispersion_partials.json	c5284a237834227b33ae4e818434b3d324f472cd0d0016b6884cd8a101a4260a
figures/example_counties.json	32e2dc507cf27a8d8ef8e47f8aa8352b11ff9a886f1872af7d6c9f5eb07a8232
figures/ext_by_cutoff.json	cb056155db52387ece816472721c76e8257657306cfee99fea7feb8c50269768
figures/landslide_shares.json	4140795df5735dc90b90f59f9edb9f3430b121cad17b9da46a23dd3f21474b4a
figures/near_tied_sd.json	5e3c59449bdd3e963161dde8b8b0d3a10bb423c20f4474e0d72bfd7606dff632
figures/sd_by_margin.json	d99808d3ebcbffbda1bc79e7c17d8ac7e8904b4fc3cf0ec8a8cbf85473d4ccb7
figures/sd_by_place_type.json	7703748d9a9d0d0201bf1339f7572ff87568f0601f0640f02904922db6535f94
figures/side_check.json	1341b4adf2a5a5ba4213bcec84f760b77c5a1c3cc3c38126e6ecb80d5056d13a
meta.json	e260af1fb522731536555d015f996b818ab3c4e075fb043f1f9c2ef3c42535c0
public/data/precincts-within-counties/county_sd_map.json	eb9534e8c372ae01eb2b210f6b3fcff02124f3cfd187128d4fe4d31e4075f66c
refs.json	599f99d0ff52632f0953ee9d7ed096112f2155d3d572417ab8ae566107896f1a

Machine formats

Report (Markdown): https://vishalsingh.org/politics/precincts-within-counties/report.md
Every estimate (JSON): https://vishalsingh.org/politics/report/precincts-within-counties/facts.json
Table 1, figure "example_counties" (JSON): https://vishalsingh.org/politics/report/precincts-within-counties/figures/example_counties.json
Table 2, figure "landslide_shares" (JSON): https://vishalsingh.org/politics/report/precincts-within-counties/figures/landslide_shares.json
Table 3, figure "county_sd_map" (JSON): https://vishalsingh.org/politics/report/precincts-within-counties/figures/county_sd_map.json
Table 4, figure "sd_by_place_type" (JSON): https://vishalsingh.org/politics/report/precincts-within-counties/figures/sd_by_place_type.json
Table 5, figure "sd_by_margin" (JSON): https://vishalsingh.org/politics/report/precincts-within-counties/figures/sd_by_margin.json
Table 6, figure "dispersion_partials" (JSON): https://vishalsingh.org/politics/report/precincts-within-counties/figures/dispersion_partials.json
Table 7, figure "ext_by_cutoff" (JSON): https://vishalsingh.org/politics/report/precincts-within-counties/figures/ext_by_cutoff.json
Table 8, figure "near_tied_sd" (JSON): https://vishalsingh.org/politics/report/precincts-within-counties/figures/near_tied_sd.json
Table 9, figure "side_check" (JSON): https://vishalsingh.org/politics/report/precincts-within-counties/figures/side_check.json
Payload of "county_sd_map" (JSON): https://vishalsingh.org/politics/data/precincts-within-counties/county_sd_map.json
Index of every report: https://vishalsingh.org/politics/llms.txt; all reports in one file: https://vishalsingh.org/politics/llms-full.txt