{
  "alt": "Waterfall chart with a first bar for the Democratic share of all voters in 1976 to 1988, a smaller positive step for the change in the mix of voters, a larger positive step for change within groups, and a last bar for the share in 2012 to 2024. The buttons show degree holders, where almost all of the change is within groups, and voters without a degree, where a rise from the mix of voters is offset by a fall within groups.",
  "caption": "The first bar is the Democratic share in 1976 to 1988 and the last bar is the share in 2012 to 2024. The first step is the part of the change that comes from a different mix of voters across cells of sex, race and ethnicity (three groups) and age (four bands), and the second step is the part that comes from a different Democratic share inside the cells. The split is an accounting identity under these cells. The second step is not a measure of persuasion: it also holds replacement of voters, a different set of people voting, survey lean and sampling change. The buttons restrict the voters by degree.",
  "data": [
    {
      "conf_high": 47.3735,
      "conf_low": 44.4876,
      "kind": "start",
      "n": 4770,
      "step": "Democratic share, 1976 to 1988",
      "topic": "All two-party voters",
      "value": 45.9306
    },
    {
      "conf_high": 3.77889,
      "conf_low": 2.09169,
      "kind": "delta",
      "n": 21554,
      "step": "Change in the mix of voters",
      "topic": "All two-party voters",
      "value": 2.91607
    },
    {
      "conf_high": 6.84684,
      "conf_low": 3.55921,
      "kind": "delta",
      "n": 21554,
      "step": "Change within groups of the same sex, race and age",
      "topic": "All two-party voters",
      "value": 5.28451
    },
    {
      "conf_high": 55.1833,
      "conf_low": 53.079,
      "kind": "end",
      "n": 16784,
      "step": "Democratic share, 2012 to 2024",
      "topic": "All two-party voters",
      "value": 54.1312
    },
    {
      "conf_high": 42.2262,
      "conf_low": 36.2431,
      "kind": "start",
      "n": 1063,
      "step": "Democratic share, 1976 to 1988",
      "topic": "Voters with a four-year degree",
      "value": 39.2346
    },
    {
      "conf_high": 2.92758,
      "conf_low": -0.142625,
      "kind": "delta",
      "n": 8689,
      "step": "Change in the mix of voters",
      "topic": "Voters with a four-year degree",
      "value": 1.12856
    },
    {
      "conf_high": 24.789,
      "conf_low": 18.0309,
      "kind": "delta",
      "n": 8689,
      "step": "Change within groups of the same sex, race and age",
      "topic": "Voters with a four-year degree",
      "value": 21.6659
    },
    {
      "conf_high": 63.4864,
      "conf_low": 60.5719,
      "kind": "end",
      "n": 7626,
      "step": "Democratic share, 2012 to 2024",
      "topic": "Voters with a four-year degree",
      "value": 62.0292
    },
    {
      "conf_high": 49.442,
      "conf_low": 46.1437,
      "kind": "start",
      "n": 3673,
      "step": "Democratic share, 1976 to 1988",
      "topic": "Voters without a four-year degree",
      "value": 47.7928
    },
    {
      "conf_high": 5.86318,
      "conf_low": 3.53512,
      "kind": "delta",
      "n": 12652,
      "step": "Change in the mix of voters",
      "topic": "Voters without a four-year degree",
      "value": 4.69923
    },
    {
      "conf_high": -1.49601,
      "conf_low": -5.4097,
      "kind": "delta",
      "n": 12652,
      "step": "Change within groups of the same sex, race and age",
      "topic": "Voters without a four-year degree",
      "value": -3.1576
    },
    {
      "conf_high": 50.7772,
      "conf_low": 47.8917,
      "kind": "end",
      "n": 8979,
      "step": "Democratic share, 2012 to 2024",
      "topic": "Voters without a four-year degree",
      "value": 49.3344
    }
  ],
  "id": "vote_split",
  "notes": [
    "The first and last bars carry Kish intervals and the two steps carry bootstrap intervals. The cells combine sex, race and ethnicity (white non-Hispanic, Black non-Hispanic, Hispanic or another race) and four age bands; a respondent with a missing value forms a cell of its own. A cell with no respondents in one period takes the other period's Democratic share, so it adds nothing to the within-cell term.",
    "Intervals come from a bootstrap that resamples respondents within each election (400 replicates, seed 12345). The split is symmetric between the mix and the within-cell change."
  ],
  "source": "ANES Cumulative Data File, 1976 to 1988 and 2012 to 2024; weighted (weight_postelection where the file has one, else weight; each election has the same total weight); two-party presidential voters",
  "spec": {
    "format": {
      "digits": 1
    },
    "kind": "kind",
    "step": "step",
    "value": "value",
    "valueLabel": "Democratic share (%) and change (points)"
  },
  "subtitle": "Change in the Democratic share of two-party presidential voters from 1976 to 1988 to 2012 to 2024, split into the mix of voters across sex, race and age cells and change within cells, percent and percentage points; ANES; the buttons switch the voters",
  "table": {
    "columns": [
      {
        "key": "topic",
        "label": "Voters"
      },
      {
        "key": "step",
        "label": "Step"
      },
      {
        "format": {
          "digits": 1
        },
        "key": "value",
        "label": "Value"
      },
      {
        "format": {
          "digits": 1
        },
        "key": "conf_low",
        "label": "95% CI low"
      },
      {
        "format": {
          "digits": 1
        },
        "key": "conf_high",
        "label": "95% CI high"
      },
      {
        "format": {
          "thousands": true
        },
        "key": "n",
        "label": "n"
      }
    ]
  },
  "title": "The mix of voters accounts for {fact:vs_all_comp} points of the change in the Democratic share and change within groups of the same sex, race and age for {fact:vs_all_within} points",
  "type": "waterfall",
  "views": [
    {
      "filter": {
        "topic": "All two-party voters"
      },
      "id": "all",
      "label": "All voters"
    },
    {
      "filter": {
        "topic": "Voters with a four-year degree"
      },
      "id": "deg",
      "label": "Four-year degree",
      "title": "Among degree holders the mix of voters accounts for {fact:vs_deg_comp} points of the change in the Democratic share and change within groups for {fact:vs_deg_within} points"
    },
    {
      "filter": {
        "topic": "Voters without a four-year degree"
      },
      "id": "nod",
      "label": "No four-year degree",
      "title": "Among voters without a degree the Democratic share barely moved, with a mix term of {fact:vs_nod_comp} points and a within-group term of {fact:vs_nod_within} points"
    }
  ],
  "width": "wide"
}