POLLING RESEARCHHistorical evidence · through 2024

Presidential polls: the national vote and the state map.

The popular vote and the Electoral College are different outcomes. Start with a consistently evaluated modern series, then examine one firm’s longer history separately.

THE RESULT BENCHMARK

What the national vote actually was.

Margins below use FEC candidate counts divided by all counted presidential votes, keeping third parties in the denominator.

National popular-vote margins. These are not Electoral College outcomes.
ElectionDemocratic candidateRepublican candidateActual D–R marginReconstructed mean polled margin*
2000 ↗Al GoreGeorge W. BushD +0.5R +2.8
2004 ↗John KerryGeorge W. BushR +2.5R +1.1
2008 ↗Barack ObamaJohn McCainD +7.3D +7.2
2012 ↗Barack ObamaMitt RomneyD +3.9D +0.9
2016 ↗Hillary ClintonDonald TrumpD +2.1D +3.1
2020 ↗Joe BidenDonald TrumpD +4.5D +8.2
2024 ↗Kamala HarrisDonald TrumpR +1.5D +1.0

*Approximate reconstruction: actual national margin plus AAPOR’s rounded mean signed error. This is not a contemporaneously published polling average. Gore (2000) and Clinton (2016) led the popular vote while losing the presidency.

THE LONGER RECORD

Gallup’s final estimates, back to 1936.

One polling organization, changing methods, and varying fieldwork windows. This is historical context—not a 90-year industry average.

Absolute error in the two-candidate-normalized margin

Gallup final presidential estimate error, two-party normalized, 1936–201204812193619481960197219841996200820121936: 13.57 pp; 1 estimates1940: 5.95 pp; 1 estimates1944: 4.55 pp; 1 estimates1948: 9.97 pp; 1 estimates1952: 8.75 pp; 1 estimates1956: 3.51 pp; 1 estimates1960: 1.80 pp; 1 estimates1964: 5.31 pp; 1 estimates1968: 0.36 pp; 1 estimates1972: 0.37 pp; 1 estimates1976: 3.17 pp; 1 estimates1980: 7.28 pp; 1 estimates1984: 0.31 pp; 1 estimates1988: 4.12 pp; 1 estimates1992: 6.99 pp; 1 estimates1996: 2.37 pp; 1 estimates2000: 2.66 pp; 1 estimates2004: 2.49 pp; 1 estimates2008: 3.73 pp; 1 estimates2012: 4.94 pp; 1 estimates

For this historical chart only, both the poll and outcome are normalized to D + R = 100%. Historical estimates often allocated undecided voters; earlier outcome shares are rounded. Normalizing denominators does not make sampling methods or final-poll timing uniform.

Retrospective comparison · percentage points of D–R marginHistorical Gallup estimates, curated by UCSB ↗
Inspect all 20 historical estimates and their definitions
Source-reported shares; normalized margin errors are approximate.
YearPoll DPoll RActual DActual RTwo-party margin miss
193655.744.360.836.513.57
194052.048.054.744.85.95
194451.548.553.445.94.55
194844.549.549.545.19.97
195249.051.044.455.18.75
195640.559.542.057.43.51
196051.049.049.749.51.80
196464.036.061.138.55.31
196842.043.042.743.40.36
197238.062.037.560.70.37
197648.049.050.148.03.17
198044.047.041.050.77.28
198441.059.040.658.80.31
198844.056.045.653.44.12
199249.037.043.037.46.99
199652.041.049.240.72.37
200046.048.048.447.92.66
200449.049.048.350.72.49
200855.044.052.945.73.73
201249.050.051.147.24.94
THE COUNTDOWN

Does waiting make the picture clearer?

Different windows can contain different pollsters and races. These are descriptive comparisons, not a causal experiment.

Mean absolute margin error, by days to election

The interactive timing chart loads with JavaScript. Every value is also in the downloadable dataset.

Latest per firm/race within each non-overlapping midpoint window.

Retrospective comparison · percentage points of D–R marginFiveThirtyEight archive · Election.org calculations ↗
CONSEQUENTIAL MISSES

Read the case files.

1936: millions of returns, the wrong electorateLiterary DigestPoll R +14.2 → result D +24.9 · miss 39.1 ppR +25D +25
1936 · President

1936: millions of returns, the wrong electorate

A huge voluntary return cannot guarantee a representative sample.

Read the evidence and analysis →
1948: the Dewey lead that disappearedGallupPoll R +5.0 → result D +4.4 · miss 9.4 ppR +5D +5
1948 · President

1948: the Dewey lead that disappeared

The sampling and timing of a poll matter more than confidence in its winner call.

Read the evidence and analysis →
1980: the right winner, a much larger victoryGallupPoll R +3.0 → result R +9.7 · miss 6.7 ppR +10D +10
1980 · President

1980: the right winner, a much larger victory

Calling the winner correctly can conceal a substantial error in the victory margin.

Read the evidence and analysis →
2016: small state margins, consequential polling missesWisconsinPoll D +5.3 → result R +0.8 · miss 6.1 ppR +10D +10
2016 · President

2016: small state margins, consequential polling misses

A reasonably close national popular-vote estimate can coexist with consequential errors in the states that decide the presidency.

Read the evidence and analysis →
Iowa 2024: a striking miss, not a settled explanationSelzer / Iowa PollPoll D +3.0 → result R +13.2 · miss 16.2 ppR +15D +15
2024 · President

Iowa 2024: a striking miss, not a settled explanation

One prominent outlier can dominate the election story. Evaluate it against the result and other polls without pretending that its cause has been established.

Read the evidence and analysis →
OPEN THE NOTEBOOK

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