Chapter 4.1 · Report

The abortion sort

In the American National Election Studies, the share saying abortion should always be allowed was 3.5 points higher among Democrats than Republicans in 1980 and 52.3 points higher in 2024.

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

The abortion sort

Chapter

4.1 (Part IV, Issues move on different schedules; Coalitions and political differences)

Question

How did abortion move from a cross-cutting issue to a partisan divide?

Dek

In the American National Election Studies, the share saying abortion should always be allowed was 3.5 points higher among Democrats than Republicans in 1980 and 52.3 points higher in 2024.

Grain

individuals

Status

draft

Published

30 September 2026

Updated

not revised

Data sources

ANES Cumulative Data File. Cumulative Data File 1948-2024, four-category abortion item (VCF0838) in the 17 studies from 1980 to 2024; mode weights for 2012, 2016 and 2024; years: 1948-2024 (33 study years; even years only after 2004; no 2006, 2010 or 2014 study); weights: weight (VCF0009z, which equals 1 for every respondent from 1980 to 1990); weight_ftf and weight_web for the mode split
ANES 2024 Time Series. 2024 Time Series, attendance items V241439 and V241440, used for the 2024 attendance groups; years: 2024 (pre-election and post-election interviews); weights: V240107a, the pre-election weight that the cumulative file uses for 2024
General Social Survey. Cumulative data 1972-2024, abany asked in 29 surveys from 1977 to 2024; interview mode joined from the raw file; years: 1972-2024 (35 study years); weights: weight_use (wtssnrps from 2004, wtssps before)

Canonical URL

https://vishalsingh.org/politics/the-abortion-sort

Markdown

https://vishalsingh.org/politics/the-abortion-sort/report.md

BibTeX

@misc{singh2026theabortionsort,
  author = {Singh, Vishal},
  title = {The abortion sort},
  year = {2026},
  url = {https://vishalsingh.org/politics/the-abortion-sort},
  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
weighted Democratic share minus weighted Republican share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	1980	3.5	95% CI −1.8 to 8.8	1,313	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File	anes_gap_1980
weighted Democratic share minus weighted Republican share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2024	52.3	95% CI 48.8 to 55.9	4,666	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File	anes_gap_2024
weighted share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic identifiers (leaners included) who answered the ANES abortion question	2024	73.7%	95% CI 71.2% to 76.2%	2,459	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File	anes_dem_2024
weighted share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Republican identifiers (leaners included) who answered the ANES abortion question	2024	21.4%	95% CI 18.9% to 23.8%	2,207	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File	anes_rep_2024
weighted share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic identifiers (leaners included) who answered the ANES abortion question	1980	37.3%	95% CI 34.0% to 40.7%	801	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File	anes_dem_1980
weighted share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Republican identifiers (leaners included) who answered the ANES abortion question	1980	33.8%	95% CI 29.7% to 37.9%	512	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File	anes_rep_1980
weighted Democratic share minus weighted Republican share; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Democratic and Republican identifiers (leaners included) who answered the GSS abany question	1980	2.5	95% CI −4.6 to 9.5	1,165	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey	gss_gap_1980
weighted Democratic share minus weighted Republican share; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Democratic and Republican identifiers (leaners included) who answered the GSS abany question	2024	47.5	95% CI 41.4 to 53.5	1,534	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey	gss_gap_2024
count of respondents who answered the question in the 17 studies that asked it	ANES respondents who answered the abortion question	1980-2024	45,017			none (count)	ANES Cumulative Data File	n_anes_item
count of ANES study years with the item	ANES studies that asked the abortion question	1980-2024	17			none (count)	ANES Cumulative Data File	n_anes_waves
count of respondents who answered abany	GSS respondents who answered the abany question	1977-2024	41,398			none (count)	General Social Survey	n_gss_item
count of GSS survey years with the item	GSS survey years that asked abany	1977-2024	29			none (count)	General Social Survey	n_gss_waves

Findings

In the American National Election Studies (ANES), 73.7% of Democrats and 21.4% of Republicans said in 2024 that abortion should always be allowed as a matter of personal choice, a gap of 52.3 points. In 1980 the two shares were 37.3% and 33.8%, a gap of 3.5 points that is too small to distinguish from zero, so the gap between the parties widened over these years. The General Social Survey (GSS) asks a different question, whether a legal abortion should be possible if the woman wants it for any reason, and shows the same widening. Its gap was 2.5 points in 1980, also too small to distinguish from zero, and 47.5 points in 2024.

Both surveys ask for a position on legal abortion, and this chapter counts the most permissive answer in each: "always allowed" in the ANES and "yes" in the GSS.The ANES question asks which of four statements comes closest to the respondent's view, from "abortion should never be permitted by law" to "a woman should always be able to obtain an abortion as a matter of personal choice." The GSS question is one of seven about circumstances in which a legal abortion should be possible, and "any reason" is the most permissive. A gap is the Democratic share minus the Republican share, in points, so a positive gap means that Democrats were more likely than Republicans to give the permissive answer. Party includes leaners, and every interval is a 95% confidence interval. The change is one case of party sorting, in which an opinion that once cut across the parties comes to line up with them.Shares use the survey weights and cover respondents who answered the question: 45,017 in 17 ANES studies from 1980 to 2024 and 41,398 in 29 GSS surveys from 1977 to 2024. The ANES cumulative file gives every respondent the same weight from 1980 to 1990, so those years are unweighted. Intervals use the Kish effective sample size [1] and treat the weighted sample as if respondents had been drawn at random one by one. Both surveys draw respondents in stages, area by area, and the intervals ignore that, which can make them narrower or wider.

Political scientists call the path by which a new issue becomes part of the party system issue evolution [2]. Adams applied the account to abortion with congressional roll calls and General Social Survey data from 1972 to 1994 [3]. O'Brian finds that by 1970 opposition to abortion among ordinary voters correlated with conservative views on other issues, and by 1972 with the Republican presidential vote [4]. The two surveys used here begin in 1977 and 1980 and follow the question through 2024.

The gap opened in the early 1990s

Table 1 plots the gap in every survey year. In the ANES studies from 1980 to 1990 the interval includes zero in 5 of 6; the exception is 1984, at 6.6 (95% CI 2.3 to 10.9) points. From 1992 on, every ANES interval lies above zero. The GSS interval includes zero in 9 of the 12 surveys from 1977 to 1991. In 1977 and 1983 it lies below zero, so Republicans were more likely than Democrats to say yes, and in 1988 it lies above zero.The 1977 GSS interval treats respondents as drawn one by one. With the stages of the sample design taken into account, the 1977 gap is −6.5 (95% CI −13.6 to 0.7) points and its interval includes zero, so whether 1977 lies below zero depends on the interval method. From 1993 on the GSS interval stays above zero. The two surveys agree that there was no consistent party gap in the 1980s and that one appeared in the early 1990s. That dating takes the first survey from which every later interval lies above zero. Chapter 4.7, Sort dates by attitude dates the same gap by a threshold on a standardized scale, with one rule for every attitude.

Table 1. Democrats and Republicans grew apart on legal abortion in both surveys

From 1992 to 2000 the ANES gap was between 12.3 and 16.2 points in every study, and no step between adjacent studies in those years has an interval that excludes zero. From 2000 to 2016 the estimate rises in each study, by 16.7 (95% CI 10.2 to 23.2) points in all, but the change between adjacent studies has an interval that includes zero in 5 of the 6 steps from 2000 to 2024. The exception is the step from 2016 to 2020, taken up below.

In the GSS the gap was lower in 2024 than in 2022 by 6.0 (95% CI −4.7 to 16.7) points, a difference whose interval includes zero. The GSS estimates from 1993 to 2016 fall as well as rise between adjacent surveys, and no step between them has an interval that excludes zero.

The 2016 to 2020 rise coincides with a mode change

The largest change between adjacent ANES studies is the one from 2016 to 2020, when the gap rose by 15.2 (95% CI 10.6 to 19.8) points, from 32.9 to 48.1. The step from 1990 to 1992, 9.4 (95% CI 3.0 to 15.8) points, is the only other one whose interval excludes zero, and the two intervals overlap, so the data do not rank the two steps. The 2020 study also changed how people were interviewed. The ANES interviewed respondents mainly in person through 2008 and added a web sample next to the in-person sample in 2012, 2016 and 2024, with separate weights for each mode. The 2020 study conducted no in-person interviews, and answers were collected online, by telephone or by video [5]. A change of survey mode can change answers, and the 2020 study has no separate weights by mode, so the ANES cannot separate the mode change from a change in opinion on its own.

Four checks bear on the step (Table 2). Three compare respondents interviewed in the same mode. The first sets ANES web respondents in 2016 against the 2020 study, which was collected mostly online. The other two set GSS in-person and web respondents before 2022 against the 2022 and 2024 surveys combined, when the GSS kept in-person interviewing next to a web sample. The GSS web comparison starts in 2021, the first GSS survey conducted mostly on the web (89.2% of respondents who answered the question, counted without weights). The gap rose in each of the three, by between 14.1 and 16.9 points, and each interval lies above zero. The fourth check is the 2000 ANES, which interviewed part of its sample by telephone [6]; its gap of 16.2 (95% CI 10.8 to 21.5) points lies between the 1998 gap of 15.5 points and the 2004 gap of 18.9 points.

Table 2. The party gap rose by similar amounts within each mode

The direct comparison of web and in-person respondents in the same study, in the lower panel, changes sign across the ANES years and has an interval that includes zero in every row. The intervals are wide: their ends run from −14.3 to +16.8 points, so they do not rule out a mode difference of the size of the step. These checks do not rule out a mode effect that appears only in 2020. They show that the gap also rose by similar amounts among respondents interviewed in the same mode.

The GSS rise in 2022 and the Dobbs decision

In June 2022 the Supreme Court decided Dobbs v. Jackson Women's Health Organization, which overturned Roe v. Wade [7]. The two surveys place the last increase differently around it. The ANES gap was already 48.1 (95% CI 45.3 to 50.9) points in 2020 and rose by a further 4.2 (95% CI −0.3 to 8.7) points to 2024, an interval that includes zero. The GSS gap rose by 16.7 (95% CI 5.3 to 28.1) points between 2021 and 2022 (Table 1). Weighted, 89.2% (95% CI 86.4% to 91.9%) of the 2022 respondents who answered the question were interviewed on or after the day of the decision (82.6% without weights). That rise mixes a change from a mostly online survey to one that combined in-person and web interviews with any change in opinion, so the same-mode comparisons above are the firmer evidence.

Two studies of the period look at other outcomes. Lockhart, Gerber and Huber report, from a large panel that spans the decision, that partisans whose abortion preferences did not match their party were more likely to change their party identification afterward [8]. Cassese, Ondercin and Randall report a shift in the link between partisanship and the intensity of abortion preferences [9]. The data used here cannot observe either change, because they have no panel and no measure of intensity.

Democratic support rose by more than Republican support fell

A gap can widen because one party moves, the other moves or both do. Table 3 shows the shares behind it. In the ANES the Democratic share rose by 36.4 (95% CI 32.2 to 40.6) points between 1980 and 2024 and the Republican share fell by 12.4 (95% CI 7.6 to 17.2) points. The GSS series starts in 1977, before the ANES series, when its gap was −6.5 (95% CI −12.7 to −0.3) points. In the GSS the Democratic share rose by 45.3 (95% CI 40.0 to 50.7) points between 1977 and 2024, from 35.2% to 80.6%. The Republican share fell by 8.6 (95% CI 1.8 to 15.4) points over the same years, from 41.7% to 33.1%. Most of that GSS Republican fall came before 1998: the share was 31.1% in 1998 and has been between 28.7% and 35.0% in every GSS survey since. The questions differ, so the GSS levels are not the ANES levels, and the comparison is of direction and timing.Among all respondents who answered, including independents who lean toward neither party, the share rose by 12.1 (95% CI 9.0 to 15.3) points in the ANES and 20.6 (95% CI 16.5 to 24.6) points in the GSS, less than the Democratic share rose in each survey.

Table 3. Democratic support for legal abortion rose while Republican support fell

The gap widened within every attendance, education and birth-cohort group

A widening gap in the whole electorate could come from one kind of voter. Table 4 splits the gap by group and compares the 1980s with the 2020s. Among all ANES party identifiers the gap was 3.6 (95% CI 1.5 to 5.7) points in the 1980s and 49.8 (95% CI 47.6 to 52.0) points in the 2020s, and in every group of either survey the 2020s interval lies above the 1980s interval.

Table 4. The party gap widened in every group

The 2020s gap is not distinguishable between frequent and infrequent attenders in either survey: the difference between the two groups is −3.5 (95% CI −8.8 to 1.7) points in the ANES and +7.8 (95% CI −3.4 to 19.1) points in the GSS. Attendance relates to the level of support in both parties.In the 2020s 48.3% of Democrats and 6.2% of Republicans who attend weekly or almost weekly said abortion should always be allowed, against 79.3% and 33.6% among people who attend a few times a year or never. In the 1980s the GSS gap among infrequent attenders was −5.7 (95% CI −9.3 to −2.0) points, so Republicans were slightly more likely than Democrats to say yes. Chapter 3.8, The god gap in America takes up the political gap between frequent and infrequent worshippers.

Education starts from a different point. College graduates already differed by party in the 1980s, with a gap of 20.7 (95% CI 15.8 to 25.6) points, while the gap among people with a high school education or less was −2.1 (95% CI −4.9 to 0.7) points, an interval that includes zero. The GSS splits at a bachelor's degree and gives the same order in both periods.

Birth cohorts that were adults in both periods show a similar widening, and Table 5 follows each cohort year by year. Comparing cohorts two at a time within a survey year, the difference has an interval that excludes zero in 3 of 52 comparisons. Each of them involves the cohort born 1927 to 1942, which had the smaller gap in 1986, 1988 and 1994. From 2012 on, the difference between any two cohorts drawn in the same year has an interval that includes zero. The cohorts born 1975 to 1990 and 1991 or later are drawn from 2012 and 2020, because their earlier cells are too small to plot. In the 2020s their gaps are 48.6 (95% CI 44.4 to 52.9) and 50.4 (95% CI 44.3 to 56.5) points, and both intervals overlap those of the older cohorts.

Table 5. Birth cohorts have similar party gaps in each year

Few Democrats now say abortion should never be permitted

The shares of people out of step with their party fell on both sides. The share of Democrats who said abortion should never be permitted fell from 12.4% (95% CI 10.1% to 14.6%) in 1980 to 1.4% (95% CI 0.7% to 2.0%) in 2024, and the share of Republicans who said it should always be allowed fell from 33.8% to 21.4% (Table 6). In points the two falls were 11.0 (95% CI 8.6 to 13.4) and 12.4 (95% CI 7.6 to 17.2), and their intervals overlap. The Democratic share was 9.7% (95% CI 6.6% to 12.7%) in 2008, so most of its fall came after that year. Killian and Wilcox followed panel respondents from 1982 to 1997 and found that pro-life Democrats and pro-choice Republicans were more likely than other partisans to switch parties over that period [10].

Table 6. Each party's out-of-step share fell, to near zero for Democrats

Abortion views came to track the presidential vote

Among ANES respondents who reported voting for the Democratic or Republican presidential candidate, the correlation between the four-category abortion answer and a Democratic vote was −0.05 (95% CI −0.11 to 0.02) in 1980 and +0.59 (95% CI 0.56 to 0.62) in 2024 (Table 7). Zero means no straight-line relationship and one a perfect one. The correlation does not say what share of votes the abortion answer predicts, and party identification and ideology also move with the vote, so it does not separate the abortion answer from them. Chapter 4.7, Sort dates by attitude compares when abortion and other attitudes became partisan, and Planned, Two moralities (planned) asks whether abortion, gay rights and gender roles form one dimension.

Table 7. The correlation of abortion views with the vote rose to +0.59

What these data cannot show

Each ANES and GSS study interviews a new sample, so the gap between the parties can widen because people change their view, change their party or are replaced by new adults. The surveys cannot say which, and the panel studies cited above [10] [8] address that question with other data; Chapter 2.1, Cohort change in partisan sorting describes ideology by birth cohort, which cannot separate switching from replacement. The estimates of change between studies treat each study as a new sample of people, although the 2020 and 2024 ANES studies re-interviewed some earlier respondents, which makes those intervals conservative.

Timing is a second limit. The ANES file used here has no study between 2020 and 2024, none measured before and after the Dobbs decision within one design, and no separate weights by mode for 2020, so the chapter cannot say how much of the 2016 to 2020 change came from the change of mode. The 2022 GSS survey was mostly conducted after the decision but changed mode from 2021, and its samples within each mode are small. Its interviews before the decision were mostly on the web (86.9% of respondents who answered) and those on or after it were less so (39.9%), so a comparison of 2022 respondents before and after the decision mixes timing and mode.

Both questions measure the most permissive position. The ANES answers "permitted only in case of rape, incest or danger to the woman's life" and "permitted for other reasons once need is established" are not plotted, and neither question measures how much respondents care about the issue, which Cassese, Ondercin and Randall study [9]. The data begin in 1977 and 1980, so they cannot say when the divide started; O'Brian dates the link between abortion opposition and conservative views to 1970 [4]. The chapter splits no group by sex, and Chapter 3.6, The gender gap in attitudes and votes compares women and men on gender-role attitudes and the vote.

The group results combine years, so they describe the 1980s and the 2020s rather than any single year. The associations here do not show that abortion opinion changed party loyalty or that party loyalty changed abortion opinion.

Tables

Table 1. Democrats and Republicans grew apart on legal abortion in both surveys

Democratic minus Republican share saying abortion should always be allowed (ANES) or legal for any reason (GSS), party identifiers including leaners, 1977 to 2024; 95% intervals

Survey	Year	Gap (points)	Lower	Upper	Respondents
ANES	1980	3.5	−1.8	8.8	1,313
ANES	1982	−0.1	−5.8	5.6	1,173
ANES	1984	6.6	2.3	10.9	1,888
ANES	1986	2.7	−1.8	7.3	1,818
ANES	1988	3.5	−0.9	8.0	1,751
ANES	1990	4.7	−0.1	9.4	1,692
ANES	1992	14.1	9.8	18.3	2,097
ANES	1994	12.4	7.1	17.8	1,537
ANES	1996	12.3	6.8	17.9	1,521
ANES	1998	15.5	9.2	21.7	1,106
ANES	2000	16.2	10.8	21.5	1,532
ANES	2004	18.9	12.2	25.5	931
ANES	2008	21.7	13.8	29.7	893
ANES	2012	30.0	26.4	33.5	5,068
ANES	2016	32.9	29.2	36.6	3,630
ANES	2020	48.1	45.3	50.9	7,002
ANES	2024	52.3	48.8	55.9	4,666
GSS	1977	−6.5	−12.7	−0.3	1,299
GSS	1978	−3.8	−10.6	3.0	1,263
GSS	1980	2.5	−4.6	9.5	1,165
GSS	1982	−0.9	−7.7	5.9	1,532
GSS	1983	−7.4	−14.0	−0.8	1,322
GSS	1984	−4.7	−11.7	2.2	1,245
GSS	1985	1.9	−4.6	8.5	1,322
GSS	1987	−2.4	−8.7	3.8	1,527
GSS	1988	9.2	1.8	16.5	817
GSS	1989	4.5	−2.9	11.9	861
GSS	1990	6.4	−1.6	14.3	766
GSS	1991	2.7	−4.9	10.3	816
GSS	1993	15.3	7.9	22.7	872
GSS	1994	8.6	3.2	14.1	1,647
GSS	1996	11.3	5.8	16.8	1,513
GSS	1998	14.5	8.9	20.1	1,449
GSS	2000	12.2	6.5	17.9	1,378
GSS	2002	19.0	10.8	27.1	719
GSS	2004	17.4	9.2	25.7	700
GSS	2006	19.9	13.9	25.8	1,486
GSS	2008	11.9	4.8	19.0	1,051
GSS	2010	19.2	11.6	26.8	968
GSS	2012	23.9	16.3	31.5	966
GSS	2014	23.5	17.2	29.7	1,290
GSS	2016	21.5	15.3	27.7	1,465
GSS	2018	31.0	23.9	38.0	1,189
GSS	2021	36.8	29.6	44.0	1,044
GSS	2022	53.5	44.7	62.3	831
GSS	2024	47.5	41.4	53.5	1,534

Note: The 2012 and 2016 ANES studies combined in-person and web samples, and the 2020 study had no in-person interviews.

Note: GSS interviews were mostly in person through 2018, mostly on the web in 2021, and a mix of in-person and web in 2022 and 2024.

Note: The GSS question was first asked in 1977. The 2008 ANES asked the question of fewer respondents than any other study, so its interval is wider; its estimate lies between those of 2004 and 2012, and this chapter treats 2008 as an ordinary year.

Source: ANES Cumulative Data File, 1980-2024, and General Social Survey, 1977-2024; weighted (VCF0009z, which equals 1 for every respondent from 1980 to 1990; weight_use)

Data: vishalsingh.org/politics/report/the-abortion-sort/figures/gap_by_year.json

Table 2. The party gap rose by similar amounts within each mode

Democratic minus Republican gap in saying yes: change within one interview mode (top) and web minus in-person difference in the same study (bottom); leaners included; 95% intervals

Panel	Comparison	Gaps compared	First gap (points)	Lower	Upper	Second gap (points)	Lower	Upper	Second minus first (points)	Lower	Upper	Respondents
Change in the party gap within one mode	ANES 2016 to 2020	2016 (all respondents), then 2020	32.9	29.2	36.6	48.1	45.3	50.9	15.2	10.6	19.8	10,632
Change in the party gap within one mode	ANES web only	2016 (web respondents), then 2020 (all respondents)	31.2	26.9	35.5	48.1	45.3	50.9	16.9	11.7	22.0	9,602
Change in the party gap within one mode	GSS in person	2018 (in person), then 2022 and 2024 combined (in person)	31.6	24.2	39.0	46.4	38.1	54.8	14.9	3.7	26.0	1,954
Change in the party gap within one mode	GSS web	2021 (web), then 2022 and 2024 combined (web)	38.5	30.9	46.1	52.6	46.0	59.3	14.1	4.1	24.2	2,148
Web minus in-person party gap, same study	ANES 2012	In person, then web	26.0	19.8	32.1	32.2	27.9	36.5	6.3	−1.3	13.8	5,068
Web minus in-person party gap, same study	ANES 2016	In person, then web	37.3	30.4	44.3	31.2	26.9	35.5	−6.1	−14.3	2.1	3,630
Web minus in-person party gap, same study	ANES 2024	In person, then web	52.3	44.8	59.7	53.8	48.6	59.1	1.6	−7.5	10.7	2,714
Web minus in-person party gap, same study	GSS 2022 and 2024	In person, then web	46.4	38.1	54.8	52.6	46.0	59.3	6.2	−4.5	16.8	2,102

Note: The 2020 ANES study has no separate weights by mode, so it has no row in the bottom panel.

Note: The GSS rows combine 2022 and 2024 because one year alone leaves too few in-person or web respondents in each party.

Source: ANES Cumulative Data File, 2012, 2016, 2020 and 2024, and General Social Survey, 2018 to 2024; weighted (weight_ftf and weight_web, the ANES weights for each mode; weight_use)

Data: vishalsingh.org/politics/report/the-abortion-sort/figures/mode_check.json

Table 3. Democratic support for legal abortion rose while Republican support fell

Share saying abortion should always be allowed (ANES) or legal for any reason (GSS), by party identification including leaners; 95% intervals

Survey and item	Group	Year	Share (%)	Lower	Upper	Respondents
ANES: always allowed	Democrats	1980	37.3	34.0	40.7	801
ANES: always allowed	Democrats	1982	36.0	32.6	39.5	741
ANES: always allowed	Democrats	1984	39.4	36.5	42.4	1,032
ANES: always allowed	Democrats	1986	40.9	37.9	43.9	1,061
ANES: always allowed	Democrats	1988	37.0	33.9	40.1	938
ANES: always allowed	Democrats	1990	43.3	40.2	46.4	993
ANES: always allowed	Democrats	1992	52.8	49.9	55.6	1,201
ANES: always allowed	Democrats	1994	46.4	42.5	50.2	810
ANES: always allowed	Democrats	1996	46.1	42.4	49.8	879
ANES: always allowed	Democrats	1998	47.2	43.0	51.4	647
ANES: always allowed	Democrats	2000	47.2	43.5	50.9	868
ANES: always allowed	Democrats	2004	44.6	39.7	49.4	498
ANES: always allowed	Democrats	2008	51.0	45.9	56.2	600
ANES: always allowed	Democrats	2012	59.0	56.5	61.4	3,081
ANES: always allowed	Democrats	2016	60.4	57.7	63.0	1,915
ANES: always allowed	Democrats	2020	72.1	70.1	74.1	3,713
ANES: always allowed	Democrats	2024	73.7	71.2	76.2	2,459
ANES: always allowed	Republicans	1980	33.8	29.7	37.9	512
ANES: always allowed	Republicans	1982	36.1	31.6	40.6	432
ANES: always allowed	Republicans	1984	32.8	29.7	36.0	856
ANES: always allowed	Republicans	1986	38.2	34.7	41.6	757
ANES: always allowed	Republicans	1988	33.5	30.2	36.7	813
ANES: always allowed	Republicans	1990	38.6	35.0	42.2	699
ANES: always allowed	Republicans	1992	38.7	35.5	41.9	896
ANES: always allowed	Republicans	1994	33.9	30.1	37.7	727
ANES: always allowed	Republicans	1996	33.7	29.6	37.9	642
ANES: always allowed	Republicans	1998	31.7	27.1	36.4	459
ANES: always allowed	Republicans	2000	31.0	27.2	34.9	664
ANES: always allowed	Republicans	2004	25.7	21.3	30.2	433
ANES: always allowed	Republicans	2008	29.3	23.3	35.3	293
ANES: always allowed	Republicans	2012	29.0	26.4	31.6	1,987
ANES: always allowed	Republicans	2016	27.5	24.9	30.0	1,715
ANES: always allowed	Republicans	2020	24.0	22.1	25.9	3,289
ANES: always allowed	Republicans	2024	21.4	18.9	23.8	2,207
GSS: any reason	Democrats	1977	35.2	31.6	38.9	852
GSS: any reason	Democrats	1978	32.1	28.0	36.2	781
GSS: any reason	Democrats	1980	40.7	36.3	45.2	725
GSS: any reason	Democrats	1982	40.4	36.5	44.4	1,052
GSS: any reason	Democrats	1983	30.5	26.3	34.6	810
GSS: any reason	Democrats	1984	36.2	31.9	40.6	731
GSS: any reason	Democrats	1985	39.2	34.6	43.7	725
GSS: any reason	Democrats	1987	40.2	36.3	44.1	990
GSS: any reason	Democrats	1988	41.6	36.6	46.6	464
GSS: any reason	Democrats	1989	41.3	36.2	46.5	459
GSS: any reason	Democrats	1990	46.3	40.5	52.1	364
GSS: any reason	Democrats	1991	43.9	38.4	49.4	407
GSS: any reason	Democrats	1993	52.6	47.5	57.7	473
GSS: any reason	Democrats	1994	50.3	46.7	54.0	925
GSS: any reason	Democrats	1996	49.3	45.4	53.2	830
GSS: any reason	Democrats	1998	45.6	41.8	49.4	846
GSS: any reason	Democrats	2000	43.4	39.4	47.3	785
GSS: any reason	Democrats	2002	48.8	43.0	54.6	397
GSS: any reason	Democrats	2004	48.9	42.9	54.8	376
GSS: any reason	Democrats	2006	49.8	45.6	54.0	834
GSS: any reason	Democrats	2008	47.0	42.1	51.8	614
GSS: any reason	Democrats	2010	51.1	45.9	56.2	560
GSS: any reason	Democrats	2012	52.6	47.7	57.6	580
GSS: any reason	Democrats	2014	56.2	52.0	60.3	775
GSS: any reason	Democrats	2016	56.3	52.1	60.4	877
GSS: any reason	Democrats	2018	65.4	60.8	69.9	689
GSS: any reason	Democrats	2021	70.9	66.4	75.3	637
GSS: any reason	Democrats	2022	83.3	78.3	88.2	476
GSS: any reason	Democrats	2024	80.6	76.7	84.5	810
GSS: any reason	Republicans	1977	41.7	36.7	46.8	447
GSS: any reason	Republicans	1978	36.0	30.5	41.4	482
GSS: any reason	Republicans	1980	38.3	32.8	43.7	440
GSS: any reason	Republicans	1982	41.3	35.8	46.8	480
GSS: any reason	Republicans	1983	37.9	32.7	43.1	512
GSS: any reason	Republicans	1984	41.0	35.6	46.4	514
GSS: any reason	Republicans	1985	37.2	32.5	42.0	597
GSS: any reason	Republicans	1987	42.7	37.7	47.6	537
GSS: any reason	Republicans	1988	32.4	27.1	37.8	353
GSS: any reason	Republicans	1989	36.8	31.6	42.1	402
GSS: any reason	Republicans	1990	39.9	34.5	45.3	402
GSS: any reason	Republicans	1991	41.2	35.9	46.4	409
GSS: any reason	Republicans	1993	37.3	31.9	42.7	399
GSS: any reason	Republicans	1994	41.7	37.7	45.7	722
GSS: any reason	Republicans	1996	38.0	34.0	42.0	683
GSS: any reason	Republicans	1998	31.1	27.0	35.3	603
GSS: any reason	Republicans	2000	31.2	27.1	35.3	593
GSS: any reason	Republicans	2002	29.8	24.1	35.6	322
GSS: any reason	Republicans	2004	31.4	25.7	37.1	324
GSS: any reason	Republicans	2006	30.0	25.8	34.2	652
GSS: any reason	Republicans	2008	35.0	29.8	40.3	437
GSS: any reason	Republicans	2010	31.8	26.3	37.4	408
GSS: any reason	Republicans	2012	28.7	23.0	34.5	386
GSS: any reason	Republicans	2014	32.7	28.1	37.3	515
GSS: any reason	Republicans	2016	34.8	30.1	39.4	588
GSS: any reason	Republicans	2018	34.4	29.1	39.8	500
GSS: any reason	Republicans	2021	34.1	28.4	39.7	407
GSS: any reason	Republicans	2022	29.8	22.5	37.1	355
GSS: any reason	Republicans	2024	33.1	28.5	37.7	724

Views: ANES: always allowed (instrument = ANES: always allowed); GSS: any reason (instrument = GSS: any reason).

Note: Shaded band: the ANES mode change from 2016 to 2020 in the ANES view, and the GSS move from in-person to web interviews between 2018 and 2021 in the GSS view.

Source: ANES Cumulative Data File, 1980-2024, and General Social Survey, 1977-2024; weighted (VCF0009z, which equals 1 for every respondent from 1980 to 1990; weight_use)

Data: vishalsingh.org/politics/report/the-abortion-sort/figures/share_by_party.json

Table 4. The party gap widened in every group

Democratic minus Republican share saying yes, 1980s against 2020s, by group; party identifiers including leaners; 95% intervals

Survey and item	Group	1980s gap (points)	Lower	Upper	Respondents	2020s gap (points)	Lower	Upper	Respondents
ANES: always allowed	All partisans	3.6	1.5	5.7	7,943	49.8	47.6	52.0	11,668
ANES: always allowed	Weekly attenders	3.8	0.9	6.6	3,018	42.1	37.7	46.6	3,119
ANES: always allowed	Monthly attenders	−0.1	−6.0	5.8	1,060	43.8	36.0	51.5	986
ANES: always allowed	Yearly or never	2.8	−0.4	6.1	3,777	45.7	42.8	48.5	7,502
ANES: always allowed	High school or less	−2.1	−4.9	0.7	4,431	37.9	33.1	42.7	2,406
ANES: always allowed	Some college	10.0	5.6	14.4	1,913	51.8	48.0	55.7	3,798
ANES: always allowed	College graduate	20.7	15.8	25.6	1,544	56.0	53.0	59.0	5,343
ANES: always allowed	Born 1927 to 1942	0.7	−3.9	5.3	1,706	50.8	42.0	59.6	675
ANES: always allowed	Born 1943 to 1958	8.1	4.4	11.7	2,899	49.3	45.2	53.5	3,123
ANES: always allowed	Born 1959 to 1974	10.1	4.5	15.7	1,165	49.8	45.6	54.0	3,016
GSS: any reason	All partisans	−0.4	−2.8	2.0	9,791	45.5	41.3	49.7	3,409
GSS: any reason	Weekly attenders	3.3	−0.3	6.9	3,032	46.0	36.1	55.8	648
GSS: any reason	Monthly attenders	1.8	−3.4	6.9	2,193	42.6	32.2	53.0	573
GSS: any reason	Yearly or less	−5.7	−9.3	−2.0	4,539	38.1	32.7	43.6	2,165
GSS: any reason	No bachelor's degree	−1.1	−3.7	1.6	8,074	38.0	32.4	43.6	1,947
GSS: any reason	Bachelor's or higher	10.8	5.2	16.4	1,694	56.1	49.9	62.4	1,457
GSS: any reason	Born 1943 to 1958	2.7	−1.3	6.7	3,495	47.4	39.4	55.5	834
GSS: any reason	Born 1959 to 1974	3.1	−3.3	9.5	1,420	42.9	35.0	50.7	914

Views: ANES: always allowed (instrument = ANES: always allowed); GSS: any reason (instrument = GSS: any reason).

Note: The 1980s are the ANES studies of 1980 to 1988 and the GSS surveys of 1980 to 1989; the 2020s are the ANES studies of 2020 and 2024 and the GSS surveys of 2021, 2022 and 2024.

Note: ANES attendance groups: weekly or nearly weekly, monthly, and a few times a year or never. The 2024 attendance answers come from the ANES 2024 Time Series because the cumulative file's 2024 attendance leaves out people who said they never attend.

Note: GSS attendance groups: weekly or more, monthly to nearly weekly, and a few times a year or less. The GSS degree question has no category for some college without a degree, so the GSS view splits at a bachelor's degree.

Source: ANES Cumulative Data File, 1980-2024, with 2024 attendance from the ANES 2024 Time Series; weighted (VCF0009z, which equals 1 for every respondent from 1980 to 1990); General Social Survey, 1980-2024, weighted (weight_use); years combined after rescaling each year's weights to average one

Data: vishalsingh.org/politics/report/the-abortion-sort/figures/gap_within_groups.json

Table 5. Birth cohorts have similar party gaps in each year

ANES Democratic minus Republican share saying abortion should always be allowed, by birth cohort (years of birth); party identifiers including leaners; 95% intervals in the data table

Birth cohort	Year	Gap (points)	Lower	Upper	Respondents
1927-42	1980	14.1	3.5	24.8	315
1927-42	1982	n/a	n/a	n/a	n/a
1927-42	1984	0.0	−9.4	9.5	405
1927-42	1986	−2.0	−12.2	8.2	372
1927-42	1988	−3.4	−13.2	6.4	367
1927-42	1990	4.8	−5.7	15.3	323
1927-42	1992	9.2	−0.4	18.8	395
1927-42	1994	3.5	−7.8	14.7	318
1927-42	1996	12.3	1.2	23.5	305
1927-42	1998	n/a	n/a	n/a	n/a
1927-42	2000	19.3	7.6	31.1	274
1927-42	2004	n/a	n/a	n/a	n/a
1927-42	2008	n/a	n/a	n/a	n/a
1927-42	2012	29.9	20.0	39.7	576
1927-42	2016	n/a	n/a	n/a	n/a
1927-42	2020	49.0	38.2	59.8	456
1943-58	1980	11.4	2.3	20.6	465
1943-58	1982	0.0	−10.0	10.1	420
1943-58	1984	9.8	2.4	17.2	688
1943-58	1986	6.9	−0.5	14.3	696
1943-58	1988	9.1	1.6	16.6	630
1943-58	1990	5.1	−3.6	13.8	537
1943-58	1992	18.5	11.1	26.0	688
1943-58	1994	9.9	0.0	19.7	468
1943-58	1996	19.8	9.9	29.6	467
1943-58	1998	25.3	14.3	36.2	358
1943-58	2000	20.6	11.0	30.3	481
1943-58	2004	24.5	12.2	36.8	274
1943-58	2008	n/a	n/a	n/a	n/a
1943-58	2012	31.4	25.3	37.5	1,650
1943-58	2016	35.5	28.7	42.3	1,001
1943-58	2020	49.6	44.5	54.8	1,912
1943-58	2024	48.8	41.8	55.8	1,211
1959-74	1984	11.6	0.2	22.9	278
1959-74	1986	15.4	4.9	25.9	328
1959-74	1988	3.2	−7.0	13.3	365
1959-74	1990	4.8	−4.0	13.6	485
1959-74	1992	17.1	9.2	25.0	611
1959-74	1994	23.3	13.7	32.9	472
1959-74	1996	15.9	5.8	26.0	464
1959-74	1998	12.6	1.1	24.1	317
1959-74	2000	23.1	13.8	32.5	491
1959-74	2004	16.1	3.2	29.1	252
1959-74	2008	n/a	n/a	n/a	n/a
1959-74	2012	25.4	18.6	32.2	1,391
1959-74	2016	29.3	22.2	36.5	936
1959-74	2020	48.0	42.7	53.3	1,789
1959-74	2024	52.6	45.9	59.4	1,227
1975-90	2012	31.6	24.3	38.9	1,174
1975-90	2016	35.0	27.9	42.2	942
1975-90	2020	44.9	39.5	50.3	1,782
1975-90	2024	53.6	46.8	60.4	1,212
After 1990	2020	46.9	38.0	55.8	801
After 1990	2024	53.6	45.2	62.1	697

Note: Intervals are not drawn because five overlapping bands cannot be read; the 95% confidence intervals are in the data table.

Note: Cohort-year cells are drawn only where each party has at least 100 respondents and an effective sample of at least 100, so the cohort born 1975 to 1990 begins in 2012 and the cohort born 1991 or later in 2020. A line breaks where a cohort's cell was left out.

Source: ANES Cumulative Data File, 1980-2024; weighted (VCF0009z, which equals 1 for every respondent from 1980 to 1990)

Data: vishalsingh.org/politics/report/the-abortion-sort/figures/gap_by_cohort.json

Table 6. Each party's out-of-step share fell, to near zero for Democrats

ANES share of Democrats saying abortion should never be permitted and of Republicans saying it should always be allowed; leaners included; 95% intervals

Series	Group and answer counted	Year	Share (%)	Lower	Upper	Respondents
Dem. never	Democrats saying abortion should never be permitted	1980	12.4	10.1	14.6	801
Dem. never	Democrats saying abortion should never be permitted	1982	14.8	12.3	17.4	741
Dem. never	Democrats saying abortion should never be permitted	1984	11.7	9.8	13.7	1,032
Dem. never	Democrats saying abortion should never be permitted	1986	14.2	12.1	16.3	1,061
Dem. never	Democrats saying abortion should never be permitted	1988	13.4	11.2	15.6	938
Dem. never	Democrats saying abortion should never be permitted	1990	11.6	9.6	13.6	993
Dem. never	Democrats saying abortion should never be permitted	1992	9.7	8.0	11.3	1,201
Dem. never	Democrats saying abortion should never be permitted	1994	14.0	11.3	16.6	810
Dem. never	Democrats saying abortion should never be permitted	1996	12.0	9.6	14.4	879
Dem. never	Democrats saying abortion should never be permitted	1998	9.7	7.2	12.2	647
Dem. never	Democrats saying abortion should never be permitted	2000	11.5	9.1	13.9	868
Dem. never	Democrats saying abortion should never be permitted	2004	10.9	7.8	13.9	498
Dem. never	Democrats saying abortion should never be permitted	2008	9.7	6.6	12.7	600
Dem. never	Democrats saying abortion should never be permitted	2012	6.5	5.3	7.7	3,081
Dem. never	Democrats saying abortion should never be permitted	2016	8.4	6.9	9.9	1,915
Dem. never	Democrats saying abortion should never be permitted	2020	4.6	3.7	5.6	3,713
Dem. never	Democrats saying abortion should never be permitted	2024	1.4	0.7	2.0	2,459
Rep. always	Republicans saying abortion should always be allowed	1980	33.8	29.7	37.9	512
Rep. always	Republicans saying abortion should always be allowed	1982	36.1	31.6	40.6	432
Rep. always	Republicans saying abortion should always be allowed	1984	32.8	29.7	36.0	856
Rep. always	Republicans saying abortion should always be allowed	1986	38.2	34.7	41.6	757
Rep. always	Republicans saying abortion should always be allowed	1988	33.5	30.2	36.7	813
Rep. always	Republicans saying abortion should always be allowed	1990	38.6	35.0	42.2	699
Rep. always	Republicans saying abortion should always be allowed	1992	38.7	35.5	41.9	896
Rep. always	Republicans saying abortion should always be allowed	1994	33.9	30.1	37.7	727
Rep. always	Republicans saying abortion should always be allowed	1996	33.7	29.6	37.9	642
Rep. always	Republicans saying abortion should always be allowed	1998	31.7	27.1	36.4	459
Rep. always	Republicans saying abortion should always be allowed	2000	31.0	27.2	34.9	664
Rep. always	Republicans saying abortion should always be allowed	2004	25.7	21.3	30.2	433
Rep. always	Republicans saying abortion should always be allowed	2008	29.3	23.3	35.3	293
Rep. always	Republicans saying abortion should always be allowed	2012	29.0	26.4	31.6	1,987
Rep. always	Republicans saying abortion should always be allowed	2016	27.5	24.9	30.0	1,715
Rep. always	Republicans saying abortion should always be allowed	2020	24.0	22.1	25.9	3,289
Rep. always	Republicans saying abortion should always be allowed	2024	21.4	18.9	23.8	2,207

Note: The Republican series is the same as the Republican line in the ANES view of the earlier figure on party shares. Shaded band: the ANES mode change from 2016 to 2020.

Source: ANES Cumulative Data File, 1980-2024; weighted (VCF0009z, which equals 1 for every respondent from 1980 to 1990)

Data: vishalsingh.org/politics/report/the-abortion-sort/figures/cross_pressured.json

Table 7. The correlation of abortion views with the vote rose to +0.59

Correlation between the four-category abortion answer (higher = more permissive) and a Democratic rather than Republican presidential vote, ANES presidential-election years, 95% intervals

Year	Correlation	Lower	Upper	Respondents
1980	−0.05	−0.11	0.02	920
1984	0.11	0.06	0.16	1,341
1988	0.11	0.06	0.17	1,182
1992	0.17	0.12	0.22	1,615
1996	0.23	0.16	0.29	1,096
2000	0.24	0.18	0.30	1,092
2004	0.26	0.18	0.33	796
2008	0.32	0.24	0.40	754
2012	0.37	0.33	0.40	4,168
2016	0.42	0.38	0.46	2,577
2020	0.51	0.49	0.54	5,977
2024	0.59	0.56	0.62	3,630

Note: Respondents who reported a vote for a candidate other than the two major-party candidates are left out. Shaded band: the ANES mode change from 2016 to 2020.

Source: ANES Cumulative Data File, 1980-2024; weighted (VCF0009z, which equals 1 for every respondent from 1980 to 1990)

Data: vishalsingh.org/politics/report/the-abortion-sort/figures/vote_correlation.json

All estimates

Every fact in facts.json (95), sorted by id. The same values as JSON: facts.json.

Fact id	Value	Unit	Estimand	Population	Period	Interval	n	Weights	Source
all_1980s	3.6	percentage points	weighted Democratic share minus weighted Republican share within the group; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question, within the group	1980s (ANES 1980 to 1988)	95% CI 1.5 to 5.7	7,943	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
all_2020s	49.8	percentage points	weighted Democratic share minus weighted Republican share within the group; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question, within the group	2020s (ANES 2020 and 2024)	95% CI 47.6 to 52.0	11,668	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
anes_all_chg	12.1	percentage points	increase in the weighted all-respondent share, 2024 minus 1980 (two separate samples)	ANES respondents who answered the abortion question	1980 to 2024	95% CI 9.0 to 15.3	6,568	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_dem_1980	37.3%	percent of respondents who answered the question	weighted share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic identifiers (leaners included) who answered the ANES abortion question	1980	95% CI 34.0% to 40.7%	801	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_dem_2024	73.7%	percent of respondents who answered the question	weighted share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic identifiers (leaners included) who answered the ANES abortion question	2024	95% CI 71.2% to 76.2%	2,459	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_dem_chg	36.4	percentage points	increase in the weighted Democratic share, 2024 minus 1980 (two separate samples)	Democratic identifiers (leaners included) who answered the ANES abortion question	1980 to 2024	95% CI 32.2 to 40.6	3,260	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_gap_1980	3.5	percentage points	weighted Democratic share minus weighted Republican share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	1980	95% CI −1.8 to 8.8	1,313	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_gap_1984	6.6	percentage points	weighted Democratic share minus weighted Republican share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	1984	95% CI 2.3 to 10.9	1,888	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_gap_1992	14.1	percentage points	weighted Democratic share minus weighted Republican share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	1992	95% CI 9.8 to 18.3	2,097	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_gap_1998	15.5	percentage points	weighted Democratic share minus weighted Republican share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	1998	95% CI 9.2 to 21.7	1,106	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_gap_2000	16.2	percentage points	weighted Democratic share minus weighted Republican share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2000	95% CI 10.8 to 21.5	1,532	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_gap_2004	18.9	percentage points	weighted Democratic share minus weighted Republican share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2004	95% CI 12.2 to 25.5	931	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_gap_2016	32.9	percentage points	weighted Democratic share minus weighted Republican share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2016	95% CI 29.2 to 36.6	3,630	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_gap_2020	48.1	percentage points	weighted Democratic share minus weighted Republican share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2020	95% CI 45.3 to 50.9	7,002	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_gap_2024	52.3	percentage points	weighted Democratic share minus weighted Republican share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2024	95% CI 48.8 to 55.9	4,666	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_plateau_hi	16.2	percentage points	highest of the yearly weighted party gaps in the five ANES studies from 1992 to 2000	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	1992 to 2000			weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_plateau_lo	12.3	percentage points	lowest of the yearly weighted party gaps in the five ANES studies from 1992 to 2000	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	1992 to 2000			weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_rep_1980	33.8%	percent of respondents who answered the question	weighted share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Republican identifiers (leaners included) who answered the ANES abortion question	1980	95% CI 29.7% to 37.9%	512	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_rep_2024	21.4%	percent of respondents who answered the question	weighted share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Republican identifiers (leaners included) who answered the ANES abortion question	2024	95% CI 18.9% to 23.8%	2,207	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_rep_chg	12.4	percentage points	decrease in the weighted Republican share, 1980 minus 2024 (two separate samples)	Republican identifiers (leaners included) who answered the ANES abortion question	1980 to 2024	95% CI 7.6 to 17.2	2,719	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
anes_settled_year	1992	year	first study year from which the 95% interval of the party gap lies above zero in every later study	ANES studies	1980-2024			none (count)	ANES Cumulative Data File
att_diff_2020s	−3.5	percentage points	party gap among people who attend weekly or nearly weekly minus the gap among people who attend a few times a year or never (independent groups)	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2020s (ANES 2020 and 2024)	95% CI −8.8 to 1.7	10,621	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
att_often_dem_2020s	48.3%	percent of respondents who answered the question	weighted share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic identifiers (leaners included) who attend weekly or nearly and answered the ANES abortion question	2020s (ANES 2020 and 2024)	95% CI 44.1% to 52.5%	1,140	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
att_often_rep_2020s	6.2%	percent of respondents who answered the question	weighted share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Republican identifiers (leaners included) who attend weekly or nearly and answered the ANES abortion question	2020s (ANES 2020 and 2024)	95% CI 4.7% to 7.7%	1,979	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
att_rarely_dem_2020s	79.3%	percent of respondents who answered the question	weighted share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic identifiers (leaners included) who attend a few times a year or never and answered the ANES abortion question	2020s (ANES 2020 and 2024)	95% CI 77.6% to 80.9%	4,538	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
att_rarely_rep_2020s	33.6%	percent of respondents who answered the question	weighted share; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Republican identifiers (leaners included) who attend a few times a year or never and answered the ANES abortion question	2020s (ANES 2020 and 2024)	95% CI 31.3% to 35.9%	2,964	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
coh_7590_2020s	48.6	percentage points	weighted Democratic share minus weighted Republican share within the group; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question, within the group	2020s (ANES 2020 and 2024)	95% CI 44.4 to 52.9	2,994	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
coh_91_2020s	50.4	percentage points	weighted Democratic share minus weighted Republican share within the group; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question, within the group	2020s (ANES 2020 and 2024)	95% CI 44.3 to 56.5	1,498	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
coh_y_4358_2020	49.6	percentage points	weighted Democratic share minus weighted Republican share within the birth cohort; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question, born 1943 to 1958	2020	95% CI 44.5 to 54.8	1,912	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
coh_y_91_2020	46.9	percentage points	weighted Democratic share minus weighted Republican share within the birth cohort; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question, born 1991 to or later	2020	95% CI 38.0 to 55.8	801	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
corr_1980	−0.05	correlation coefficient, from −1 to +1	weighted Pearson correlation between the four-category abortion answer (higher = more permissive) and a Democratic vote (Fisher z interval on the Kish effective n)	ANES respondents who answered the abortion question and reported a Democratic or Republican presidential vote	1980	95% CI −0.11 to 0.02	920	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
corr_1984	+0.11	correlation coefficient, from −1 to +1	weighted Pearson correlation between the four-category abortion answer (higher = more permissive) and a Democratic vote (Fisher z interval on the Kish effective n)	ANES respondents who answered the abortion question and reported a Democratic or Republican presidential vote	1984	95% CI 0.06 to 0.16	1,341	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
corr_2024	+0.59	correlation coefficient, from −1 to +1	weighted Pearson correlation between the four-category abortion answer (higher = more permissive) and a Democratic vote (Fisher z interval on the Kish effective n)	ANES respondents who answered the abortion question and reported a Democratic or Republican presidential vote	2024	95% CI 0.56 to 0.62	3,630	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
edu_col_1980s	20.7	percentage points	weighted Democratic share minus weighted Republican share within the group; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question, within the group	1980s (ANES 1980 to 1988)	95% CI 15.8 to 25.6	1,544	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
edu_hs_1980s	−2.1	percentage points	weighted Democratic share minus weighted Republican share within the group; the ANES four-category abortion question, answer 'always allowed as a matter of personal choice'	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question, within the group	1980s (ANES 1980 to 1988)	95% CI −4.9 to 0.7	4,431	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
grp_hi_1980s	20.7	percentage points	highest of the weighted party gaps in the groups drawn in the groups figure	Democratic and Republican identifiers (leaners included) within each plotted group, ANES and GSS views together	1980s (ANES 1980 to 1988, GSS 1980 to 1989)			weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
grp_hi_2020s	56.1	percentage points	highest of the weighted party gaps in the groups drawn in the groups figure	Democratic and Republican identifiers (leaners included) within each plotted group, ANES and GSS views together	2020s (ANES 2020 and 2024, GSS 2021, 2022 and 2024)			weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
grp_lo_1980s	−5.7	percentage points	lowest of the weighted party gaps in the groups drawn in the groups figure	Democratic and Republican identifiers (leaners included) within each plotted group, ANES and GSS views together	1980s (ANES 1980 to 1988, GSS 1980 to 1989)			weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
grp_lo_2020s	37.9	percentage points	lowest of the weighted party gaps in the groups drawn in the groups figure	Democratic and Republican identifiers (leaners included) within each plotted group, ANES and GSS views together	2020s (ANES 2020 and 2024, GSS 2021, 2022 and 2024)			weight (VCF0009z; equals 1 for every respondent from 1980 to 1990), rescaled to average one within each survey year before combining	ANES Cumulative Data File
gss_after_dobbs	89.2%	percent of respondents who answered the question	weighted share interviewed on or after 24 June 2022, the date of the Dobbs decision	GSS respondents who answered the abany question in 2022	2022	95% CI 86.4% to 91.9%	1,136	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_after_dobbs_unw	82.6%	percent of respondents who answered the question	unweighted share interviewed on or after 24 June 2022 (respondent count)	GSS respondents who answered the abany question in 2022	2022		1,136	none (count)	General Social Survey
gss_all_chg	20.6	percentage points	increase in the weighted all-respondent share, 2024 minus 1977 (two separate samples)	GSS respondents who answered the abany question	1977 to 2024	95% CI 16.5 to 24.6	3,619	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_att_diff_2020s	+7.8	percentage points	party gap among people who attend weekly or more minus the gap among people who attend a few times a year or less (independent groups)	Democratic and Republican identifiers (leaners included) who answered the GSS abany question	2020s (GSS 2021, 2022 and 2024)	95% CI −3.4 to 19.1	2,813	weight_use, rescaled to average one within each survey year before combining	General Social Survey
gss_att_rarely_1980s	−5.7	percentage points	weighted Democratic share minus weighted Republican share within the group; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Democratic and Republican identifiers (leaners included) who answered the GSS abany question, within the group	1980s (GSS 1980 to 1989)	95% CI −9.3 to −2.0	4,539	weight_use, rescaled to average one within each survey year before combining	General Social Survey
gss_dem_1977	35.2%	percent of respondents who answered the question	weighted share; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Democratic identifiers (leaners included) who answered the GSS abany question	1977	95% CI 31.6% to 38.9%	852	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_dem_2024	80.6%	percent of respondents who answered the question	weighted share; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Democratic identifiers (leaners included) who answered the GSS abany question	2024	95% CI 76.7% to 84.5%	810	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_dem_chg	45.3	percentage points	increase in the weighted Democratic share, 2024 minus 1977 (two separate samples)	Democratic identifiers (leaners included) who answered the GSS abany question	1977 to 2024	95% CI 40.0 to 50.7	1,662	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_fall_2224	6.0	percentage points	decrease in the weighted party gap, 2022 minus 2024 (two separate samples)	Democratic and Republican identifiers (leaners included) who answered the GSS abany question	2022 to 2024	95% CI −4.7 to 16.7	2,365	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_gap_1977	−6.5	percentage points	weighted Democratic share minus weighted Republican share; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Democratic and Republican identifiers (leaners included) who answered the GSS abany question	1977	95% CI −12.7 to −0.3	1,299	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_gap_1977_design	−6.5	percentage points	weighted Democratic share minus weighted Republican share; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes; interval from a Taylor linearisation that uses the survey strata (vstrat) and primary sampling units (vpsu)	Democratic and Republican identifiers (leaners included) who answered the GSS abany question	1977	95% CI −13.6 to 0.7	1,299	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_gap_1980	2.5	percentage points	weighted Democratic share minus weighted Republican share; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Democratic and Republican identifiers (leaners included) who answered the GSS abany question	1980	95% CI −4.6 to 9.5	1,165	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_gap_2022	53.5	percentage points	weighted Democratic share minus weighted Republican share; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Democratic and Republican identifiers (leaners included) who answered the GSS abany question	2022	95% CI 44.7 to 62.3	831	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_gap_2024	47.5	percentage points	weighted Democratic share minus weighted Republican share; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Democratic and Republican identifiers (leaners included) who answered the GSS abany question	2024	95% CI 41.4 to 53.5	1,534	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_rep_1977	41.7%	percent of respondents who answered the question	weighted share; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Republican identifiers (leaners included) who answered the GSS abany question	1977	95% CI 36.7% to 46.7%	447	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_rep_1998	31.1%	percent of respondents who answered the question	weighted share; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Republican identifiers (leaners included) who answered the GSS abany question	1998	95% CI 27.0% to 35.3%	603	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_rep_2024	33.1%	percent of respondents who answered the question	weighted share; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Republican identifiers (leaners included) who answered the GSS abany question	2024	95% CI 28.5% to 37.7%	724	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_rep_chg	8.6	percentage points	decrease in the weighted Republican share, 1977 minus 2024 (two separate samples)	Republican identifiers (leaners included) who answered the GSS abany question	1977 to 2024	95% CI 1.8 to 15.4	1,171	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_rep_late_hi	35.0%	percent of respondents who answered the question	highest of the yearly weighted Republican shares in the 14 GSS surveys from 1998 to 2024; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Republican identifiers (leaners included) who answered the GSS abany question	1998 to 2024			weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_rep_late_lo	28.7%	percent of respondents who answered the question	lowest of the yearly weighted Republican shares in the 14 GSS surveys from 1998 to 2024; the GSS abany question (a legal abortion should be possible if the woman wants it for any reason), answer yes	Republican identifiers (leaners included) who answered the GSS abany question	1998 to 2024			weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
gss_settled_year	1993	year	first survey year from which the 95% interval of the party gap lies above zero in every later survey	GSS surveys	1977-2024			none (count)	General Social Survey
gss_web_post_dobbs	39.9%	percent of respondents who answered the question	share interviewed on the web (unweighted respondent count)	GSS respondents who answered the abany question in 2022, interviewed on or after 24 June	2022		938	none (count)	General Social Survey
gss_web_pre_dobbs	86.9%	percent of respondents who answered the question	share interviewed on the web (unweighted respondent count)	GSS respondents who answered the abany question in 2022, interviewed before 24 June	2022		198	none (count)	General Social Survey
gss_web_share_2021	89.2%	percent of respondents who answered the question	share of respondents interviewed on the web (unweighted count)	GSS respondents who answered the abany question in 2021	2021		1,328	none (unweighted count)	General Social Survey
mode_ci_high_max	+16.8	percentage points	highest upper end of the four 95% intervals for web minus in-person party gaps	ANES (2012, 2016, 2024) and GSS (2022 and 2024 combined) Democratic and Republican identifiers	2012 to 2024			weight_web and weight_ftf; weight_use	ANES Cumulative Data File
mode_ci_low_min	−14.3	percentage points	lowest lower end of the four 95% intervals for web minus in-person party gaps	ANES (2012, 2016, 2024) and GSS (2022 and 2024 combined) Democratic and Republican identifiers	2012 to 2024			weight_web and weight_ftf; weight_use	ANES Cumulative Data File
mode_diff_2012	+6.3	percentage points	web respondents' weighted party gap minus in-person respondents' gap (two separate samples)	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2012	95% CI −1.3 to 13.8	5,068	weight_web and weight_ftf (VCF0009z mode weights)	ANES Cumulative Data File
mode_diff_2016	−6.1	percentage points	web respondents' weighted party gap minus in-person respondents' gap (two separate samples)	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2016	95% CI −14.3 to 2.1	3,630	weight_web and weight_ftf (VCF0009z mode weights)	ANES Cumulative Data File
mode_diff_2024	+1.6	percentage points	web respondents' weighted party gap minus in-person respondents' gap (two separate samples)	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2024	95% CI −7.5 to 10.7	2,714	weight_web and weight_ftf (VCF0009z mode weights)	ANES Cumulative Data File
mode_diff_gss	+6.2	percentage points	web respondents' weighted party gap minus in-person respondents' gap (two separate samples)	Democratic and Republican identifiers (leaners included) who answered the GSS abany question	2022 and 2024 combined	95% CI −4.5 to 16.8	2,102	weight_use, rescaled to average one within each survey year before combining	General Social Survey
mode_rise_hi	16.9	percentage points	highest of the three rises in the weighted party gap within one interview mode: ANES web respondents in 2016 against all respondents in 2020, GSS in-person respondents in 2018 against 2022 and 2024 combined, GSS web respondents in 2021 against 2022 and 2024 combined	Democratic and Republican identifiers (leaners included) interviewed in one mode	2016 to 2020 (ANES web respondents in 2016), 2018 to 2022 and 2024 (GSS in person), 2021 to 2022 and 2024 (GSS web)			weight_web and VCF0009z (ANES); weight_use (GSS)	ANES Cumulative Data File
mode_rise_lo	14.1	percentage points	lowest of the three rises in the weighted party gap within one interview mode: ANES web respondents in 2016 against all respondents in 2020, GSS in-person respondents in 2018 against 2022 and 2024 combined, GSS web respondents in 2021 against 2022 and 2024 combined	Democratic and Republican identifiers (leaners included) interviewed in one mode	2016 to 2020 (ANES web respondents in 2016), 2018 to 2022 and 2024 (GSS in person), 2021 to 2022 and 2024 (GSS web)			weight_web and VCF0009z (ANES); weight_use (GSS)	ANES Cumulative Data File
n_anes_early	6	studies	count of ANES study years from 1980 to 1990 with the item	ANES studies from 1980 to 1990	1980-1990			none (count)	ANES Cumulative Data File
n_anes_early_zero	5	studies	count of study years in which the 95% interval of the party gap includes zero	ANES studies from 1980 to 1990	1980-1990			none (count)	ANES Cumulative Data File
n_anes_item	45,017	respondents	count of respondents who answered the question in the 17 studies that asked it	ANES respondents who answered the abortion question	1980-2024			none (count)	ANES Cumulative Data File
n_anes_steps_post2000	6	steps	count of steps between adjacent ANES studies from 2000 to 2024 (2000 to 2004, 2004 to 2008, 2008 to 2012, 2012 to 2016, 2016 to 2020, 2020 to 2024)	adjacent ANES study pairs from 2000 to 2024	2000-2024			none (count)	ANES Cumulative Data File
n_anes_steps_post2000_zero	5	steps	count of those steps in which the 95% interval of the change in the party gap includes zero	adjacent ANES study pairs from 2000 to 2024	2000-2024			none (count)	ANES Cumulative Data File
n_anes_waves	17	studies	count of ANES study years with the item	ANES studies that asked the abortion question	1980-2024			none (count)	ANES Cumulative Data File
n_coh_pairs	52	comparisons	count of pairs of cohorts (born 1927 to 1942, 1943 to 1958, 1959 to 1974, 1975 to 1990, 1991 or later) with a plotted party gap in the same study	pairs of birth cohorts drawn in the same ANES survey year	1980-2024			none (count)	ANES Cumulative Data File
n_coh_pairs_excl	3	comparisons	count of those pairs in which the 95% interval of the difference between the two cohorts' party gaps excludes zero	pairs of birth cohorts drawn in the same ANES survey year	1980-2024			none (count)	ANES Cumulative Data File
n_gss_early	12	surveys	count of GSS survey years from 1977 to 1991 with the item	GSS surveys from 1977 to 1991	1977-1991			none (count)	General Social Survey
n_gss_early_zero	9	surveys	count of survey years in which the 95% interval of the party gap includes zero	GSS surveys from 1977 to 1991	1977-1991			none (count)	General Social Survey
n_gss_item	41,398	respondents	count of respondents who answered abany	GSS respondents who answered the abany question	1977-2024			none (count)	General Social Survey
n_gss_waves	29	surveys	count of GSS survey years with the item	GSS survey years that asked abany	1977-2024			none (count)	General Social Survey
prolife_dem_1980	12.4%	percent of respondents who answered the question	weighted share; the ANES answer 'by law, abortion should never be permitted'	Democratic identifiers (leaners included) who answered the ANES abortion question	1980	95% CI 10.1% to 14.6%	801	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
prolife_dem_2008	9.7%	percent of respondents who answered the question	weighted share; the ANES answer 'by law, abortion should never be permitted'	Democratic identifiers (leaners included) who answered the ANES abortion question	2008	95% CI 6.6% to 12.7%	600	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
prolife_dem_2024	1.4%	percent of respondents who answered the question	weighted share; the ANES answer 'by law, abortion should never be permitted'	Democratic identifiers (leaners included) who answered the ANES abortion question	2024	95% CI 0.7% to 2.0%	2,459	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
prolife_dem_chg	11.0	percentage points	decrease in the weighted share answering 'never permitted', 1980 minus 2024 (two separate samples)	Democratic identifiers (leaners included) who answered the ANES abortion question	1980 to 2024	95% CI 8.6 to 13.4	3,260	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
step_anes_0016	16.7	percentage points	change in the weighted party gap, 2016 minus 2000 (two separate samples)	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2000 to 2016	95% CI 10.2 to 23.2	5,162	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
step_anes_1620	15.2	percentage points	change in the weighted party gap, 2020 minus 2016 (two separate samples)	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2016 to 2020	95% CI 10.6 to 19.8	10,632	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
step_anes_2024	4.2	percentage points	change in the weighted party gap, 2024 minus 2020 (two separate samples)	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2020 to 2024	95% CI −0.3 to 8.7	11,668	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
step_anes_9092	9.4	percentage points	change in the weighted party gap, 1992 minus 1990 (two separate samples)	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	1990 to 1992	95% CI 3.0 to 15.8	3,789	weight (VCF0009z; equals 1 for every respondent from 1980 to 1990, so those years are unweighted)	ANES Cumulative Data File
step_anes_web16_20	16.9	percentage points	change in the weighted party gap, 2020 (all respondents, mostly online) minus 2016 (web respondents only)	Democratic and Republican identifiers (leaners included) who answered the ANES abortion question	2016 (web respondents) to 2020	95% CI 11.7 to 22.0	9,602	weight_web (VCF0009z web weight) for 2016 web respondents; weight (VCF0009z) for 2020	ANES Cumulative Data File
step_gss_2122	16.7	percentage points	change in the weighted party gap, 2022 minus 2021, all modes (two separate samples)	Democratic and Republican identifiers (leaners included) who answered the GSS abany question	2021 to 2022	95% CI 5.3 to 28.1	1,875	weight_use (wtssnrps from 2004, wtssps before)	General Social Survey
step_gss_ftf	14.9	percentage points	change in the weighted party gap among in-person respondents (two separate samples)	in-person GSS respondents, Democratic and Republican identifiers (leaners included) who answered the GSS abany question	2018 to 2022 and 2024 combined	95% CI 3.7 to 26.0	1,954	weight_use, rescaled to average one within each survey year before combining	General Social Survey
step_gss_web	14.1	percentage points	change in the weighted party gap among web respondents (two separate samples)	web GSS respondents, Democratic and Republican identifiers (leaners included) who answered the GSS abany question	2021 to 2022 and 2024 combined	95% CI 4.1 to 24.2	2,148	weight_use, rescaled to average one within each survey year before combining	General Social Survey

Definitions

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.
Partisan leaner: A respondent who first says they are independent but, when asked, says they lean toward one party. Most figures group leaners with the party they lean toward, and each chapter says which grouping it uses.
Confidence interval: A range around an estimate that would contain the true value in 95% of repeated samples if the sampling model held. The book reports 95% intervals unless it says otherwise.
Party sorting: The alignment of party with other traits, such as ideology, religion, race and place, so that people who share a party also tend to share those traits.
Effective sample size: The number of equally weighted respondents that would give the same precision as the weighted sample. It is smaller than the raw count when the weights vary a lot, and it sets how wide the confidence interval is.
Survey weights: Numbers that scale each respondent so the sample matches the population on known traits such as age, race, education and region. A weighted average counts a respondent with a large weight for more than one with a small weight.
Survey mode: How respondents were interviewed: in person, by phone, on paper or online. Mode can change answers, so a change in mode can look like a change in opinion.
Cohort: People born in the same period, such as the same decade. Comparing cohorts shows whether a difference comes from when people were born, as distinct from their age or the year they were surveyed.
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.

Methods

Sample. ANES Cumulative Data File respondents who answered the four-category abortion question (VCF0838: 1 abortion never permitted, 2 only for rape, incest or danger to the woman's life, 3 for other reasons once need is established, 4 always allowed as a matter of personal choice; the 'other' answer is missing): 45,017 respondents in 17 studies from 1980 to 2024, of whom 39,618 name or lean toward a party. GSS respondents who answered abany (a legal abortion should be possible if the woman wants it for any reason; asked from 1977 to 2024 and absent from the file before 1977): 41,398 respondents in 29 surveys, 34,037 of them Democratic or Republican identifiers.

Party and estimand. Leaners count with their party (ANES pid_7pt 1 to 3 Democratic and 5 to 7 Republican; GSS partyid 0 to 2 and 4 to 6). Independents who lean toward neither party and members of other parties are left out of the party lines and the gap and are counted only in the all-respondent changes given in the text. In each survey year the estimand is the weighted share choosing the most permissive answer (ANES 'always allowed', GSS yes) among Democrats and among Republicans; the party gap is the Democratic share minus the Republican share, in percentage points, which is minus the Republican coefficient in a weighted linear probability model of the answer on a Republican indicator, the form used in earlier versions of this analysis.

Weights. ANES weight VCF0009z, which equals 1 for every respondent from 1980 to 1990, so the 1980 endpoint and the 1980s groups are unweighted; GSS weight_use (wtssnrps from 2004, wtssps before).

Mode. ANES mode-specific estimates use weight_ftf and weight_web, the weights for in-person and web respondents, which exist for 2008, 2012, 2016 and 2024 (2008 was a single-mode in-person study; 2020 has no separate weights by mode). The 2024 mode groups are the newly recruited in-person and web samples (the ANES calls them fresh samples), 1,017 in person and 1,955 on the web of the 5,021 item respondents; the panel and paper respondents are in neither. The GSS interview mode (in person, telephone, web or other) is joined from the raw file.

Intervals. 95% intervals come from the Kish effective sample size with a normal approximation, which treats the weighted sample as a simple random sample and ignores the strata and clusters of the sampling design. For one estimate, the GSS 1977 gap, a design-based interval (Taylor linearisation with the GSS strata vstrat and primary sampling units vpsu) is also reported, because the two methods disagree about whether it lies below zero. Differences between two independent estimates (party gaps, changes over time, mode differences) combine the two standard errors in quadrature. Adjacent ANES studies are treated as independent although the 2020 and 2024 studies re-interviewed some earlier respondents, which makes those intervals conservative. Correlations use Fisher z on the Kish effective sample size.

Suppression. A party cell in a yearly series needs at least 150 respondents and an effective sample of at least 100. A party cell in a group, mode or cohort estimate needs at least 100 respondents and an effective sample of at least 100, and a gap needs both cells to clear the floor.

Periods and groups. The 1980s combine ANES 1980 to 1988 and GSS 1980 to 1989, and the 2020s combine ANES 2020 and 2024 and GSS 2021, 2022 and 2024, after rescaling each year's weights to average one so that years count in proportion to their respondents. Attendance has three categories (ANES weekly or almost weekly, once or twice a month, a few times a year or never; GSS attend 7 and 8, 4 to 6, and 0 to 3), with the 2024 ANES values rebuilt from the 2024 Time Series (V241439, V241440) because the cumulative file leaves out respondents who said they never attend. Education has three ANES categories and two GSS categories (a bachelor's degree or higher, or not). Birth cohort uses the ANES cohort categories and, for the GSS, survey year minus age.

Vote. The weighted Pearson correlation between the four-category answer and a Democratic rather than Republican presidential vote, in presidential-election years.

GSS 2022 interview date. The month and day are in dateintv, which has no year, so the interviews dated in January (5 of the respondents who answered the abortion question) are counted as before the decision; counting them as after it changes the weighted share by less than one point.

What these data cannot show

Each ANES and GSS study interviews a new sample, so the gap between the parties can widen because people change their view, change their party or are replaced by new adults.
The surveys cannot say which, and the panel studies cited above [10] [8] address that question with other data; Chapter 2.1, Cohort change in partisan sorting (https://vishalsingh.org/politics/how-the-sort-happened) describes ideology by birth cohort, which cannot separate switching from replacement.
The estimates of change between studies treat each study as a new sample of people, although the 2020 and 2024 ANES studies re-interviewed some earlier respondents, which makes those intervals conservative.
Timing is a second limit.
The ANES file used here has no study between 2020 and 2024, none measured before and after the Dobbs decision within one design, and no separate weights by mode for 2020, so the chapter cannot say how much of the 2016 to 2020 change came from the change of mode.
The 2022 GSS survey was mostly conducted after the decision but changed mode from 2021, and its samples within each mode are small.
Its interviews before the decision were mostly on the web (86.9% of respondents who answered) and those on or after it were less so (39.9%), so a comparison of 2022 respondents before and after the decision mixes timing and mode.
Both questions measure the most permissive position.
The ANES answers "permitted only in case of rape, incest or danger to the woman's life" and "permitted for other reasons once need is established" are not plotted, and neither question measures how much respondents care about the issue, which Cassese, Ondercin and Randall study [9].
The data begin in 1977 and 1980, so they cannot say when the divide started; O'Brian dates the link between abortion opposition and conservative views to 1970 [4].
The chapter splits no group by sex, and Chapter 3.6, The gender gap in attitudes and votes (https://vishalsingh.org/politics/the-gender-gap) compares women and men on gender-role attitudes and the vote.
The group results combine years, so they describe the 1980s and the 2020s rather than any single year.
The associations here do not show that abortion opinion changed party loyalty or that party loyalty changed abortion opinion.

References

Kish, Leslie (1965). Survey Sampling. John Wiley and Sons.
Carmines, Edward G.; Stimson, James A. (1989). Issue Evolution: Race and the Transformation of American Politics. Princeton University Press.
Adams, Greg D. (1997). Abortion: Evidence of an Issue Evolution. American Journal of Political Science 41(3): 718-737.
O'Brian, Neil A. (2020). Before Reagan: The Development of Abortion's Partisan Divide. Perspectives on Politics 18(4): 1031-1047. doi:10.1017/S1537592719003840
American National Election Studies (2021). ANES 2020 Time Series Study Full Release: User Guide and Codebook. Stanford University and the University of Michigan. electionstudies.org/data-center/2020-time-series-study/
Burns, Nancy; Kinder, Donald R.; Rosenstone, Steven J.; Sapiro, Virginia; American National Election Studies (2001). ANES 2000 Time Series Study. Inter-university Consortium for Political and Social Research, ICPSR 3131. doi:10.3886/ICPSR03131.v1
Supreme Court of the United States (2022). Dobbs v. Jackson Women's Health Organization, 597 U.S. 215. Decided 24 June 2022. www.supremecourt.gov/opinions/21pdf/19-1392_6j37.pdf
Lockhart, Mackenzie; Gerber, Alan S.; Huber, Gregory A. (2024). Policy Shapes Partisan Identification: How Dobbs made pre-existing abortion policy preferences relevant to partisanship. Working paper, Yale University. huber.research.yale.edu/writings.html
Cassese, Erin C.; Ondercin, Heather L.; Randall, Jordan (2025). Abortion Attitudes and Polarization in the American Electorate. Elements in Gender and Politics, Cambridge University Press. doi:10.1017/9781009533119
Killian, Mitchell; Wilcox, Clyde (2008). Do Abortion Attitudes Lead to Party Switching?. Political Research Quarterly 61(4): 561-573. doi:10.1177/1065912907312981

Provenance

Pipeline version: 1.0.0
Build script: book3/chapters/the-abortion-sort/build.py (sha256 9dbc60b7d81e3a7c873ba2e0dc4f8fc642024dd93e53e95dcbdc596e085d466c)
Built on: 2026-09-30
Site commit: 16414b2c7257546a7042d0b1734657f208999f60

Inputs

File	Size (bytes)	SHA-256, first 1 MB	SHA-256, last 1 MB
data/anes/anes2024_ts/anes_timeseries_2024_spss_20260519.sav	12,757,094	3107c838755f88353d0e3e39b2c3d5f76a2888cf56a179e3acac84ab431335d2	bb318a018a39b4cf87ccc91b50a5b7c5b41746d28c0226f4a6c176e8c74966d6
data/anes/anes_cdf_clean.parquet	15,640,720	b3f0c2d8ae5673b2c40cf6df71318ea3f712cd845c4f1aad0460f28d1b022643	04f06dae56b65649291caf6cf77aab9767d9c92d0c2669c6d3655d9063970583
data/gss/gss_all_raw2024.parquet	35,044,704	6f6560d1929e8a100f576317a296ee88f777ca061ab7dbc1471cbdc7b3563538	5c3294f206beb53d9a8387fccb1983bf3088818df090bd8ed3f378adadafcf9b
data/gss/gss_sub2024.parquet	4,925,270	09c4894730735ec7ae5a057c99d97705866b0b4d485a8b14030435944f909fba	fbbacc5d2586b9f6a774f02031f3686c14fa23a0effee92366bb90a6de8e0ad3

Outputs

File	SHA-256
facts.json	62a3b6209ea71c08e6ecf9a8592b9341b23d44b0436da177e44fa33287dfc045
figures/cross_pressured.json	7db1d0286d05e3a708e689e2bbdc8ebbdd5fd80b6e76b8fd1890ac67610a18b3
figures/gap_by_cohort.json	99198a3ac8eb3e03de01df6b0a5c8552741b151a0c14ea1548affa9bda192729
figures/gap_by_year.json	509da791a54c12e9d1ee0a88daa02896c6b6a7a11571b16548ee6269e812af64
figures/gap_within_groups.json	d4302a019a1c82018810e8c13ab51d4e5750013706a86d06a7cb4187cda98b43
figures/mode_check.json	548f996565158cf4f54b3387f837549bb399160f15e60076139acc0c15e4762c
figures/share_by_party.json	b158a2138c04b08a4608ceeedc089fe9ed726c76cbec8dd468e0c3e23934f7f9
figures/vote_correlation.json	302ef79d46ab9cc5df3a4289d99a795d1f1e3bf69e66f2bd4fb9debb144fdcb8
meta.json	a29cb7718eab432f0bcc49274fd98cc237c5069ffe8eb9bff118646d6dc13806
refs.json	1d254ad9dffb2b12ac05645f204cb07b207f900fcd2ee97d62ef585450db0d46

Machine formats

Report (Markdown): https://vishalsingh.org/politics/the-abortion-sort/report.md
Every estimate (JSON): https://vishalsingh.org/politics/report/the-abortion-sort/facts.json
Table 1, figure "gap_by_year" (JSON): https://vishalsingh.org/politics/report/the-abortion-sort/figures/gap_by_year.json
Table 2, figure "mode_check" (JSON): https://vishalsingh.org/politics/report/the-abortion-sort/figures/mode_check.json
Table 3, figure "share_by_party" (JSON): https://vishalsingh.org/politics/report/the-abortion-sort/figures/share_by_party.json
Table 4, figure "gap_within_groups" (JSON): https://vishalsingh.org/politics/report/the-abortion-sort/figures/gap_within_groups.json
Table 5, figure "gap_by_cohort" (JSON): https://vishalsingh.org/politics/report/the-abortion-sort/figures/gap_by_cohort.json
Table 6, figure "cross_pressured" (JSON): https://vishalsingh.org/politics/report/the-abortion-sort/figures/cross_pressured.json
Table 7, figure "vote_correlation" (JSON): https://vishalsingh.org/politics/report/the-abortion-sort/figures/vote_correlation.json
Index of every report: https://vishalsingh.org/politics/llms.txt; all reports in one file: https://vishalsingh.org/politics/llms-full.txt