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The most common question pollsters hear around election time is “Who’s going to win?” A close second this year was “Are the polls going to be wrong again?”
Votes are still being counted, but two conclusions seem clear: Preelection polls captured the direction of this year’s election while generally understating the size of Democrats’ advantage.
Polls consistently documented the electorate’s dark mood this year, including deep dissatisfaction with President Donald Trump, even among some of his 2024 voters. That frustration was particularly focused on his economic policies.
Polls also consistently identified a wide enthusiasm gap, with Democratic supporters more interested, engaged and likely to show up to vote than Republican supporters. Indeed, Democratic supporters were also more likely to take preelection surveys, as a number of our colleagues reported.
In the end, polls found more than enough opportunities for Democratic pickups in the Senate to win a majority in the chamber, and they indicated a likely Democratic takeover of the U.S. House of Representatives. But the polling understated the size of the eventual Democratic victory in many of the major statewide races (Georgia and Texas, in particular), as well as in the overall House vote.
This analysis compares final 2026 preelection polling averages with unofficial vote counts in 27 U.S. Senate and governor races and an estimate of votes cast for U.S. House of Representatives.
Why did we do this?
Pew Research Center does research to help the public, media and decision-makers understand important topics.
How did we do this?
We pulled polling averages from three sources: RealClearPolitics, Silver Bulletin and FiftyPlusOne. Each was recorded as the Democratic candidate’s share minus the Republican’s.
Election results are unofficial vote counts as of Nov. 4, 2026, drawn from official state election results websites and from vote counts reported by news sources.
We calculate polling error as the Democratic margin in the vote count minus the Democratic margin in the polling average. This analysis uses signed error, which keeps the direction of the miss consistent.
In fact, preelection polling estimates understated the Democratic margin by at least 2 points in 23 of 27 races for governor and U.S. Senate with available data at the time of this writing. The mean understatement across all 27 races was about 4 percentage points.
The gap ranged from less than 0.5 percentage points to about 9 points. One exception was Pennsylvania, where polls overstated the Democratic margin in the governor’s race by a little less than 3 points. Incumbent Gov. Josh Shapiro still won reelection by about 22 points.
Many pollsters provide what’s known as the “generic House ballot,” which asks voters which party’s candidate they intend to support in their local House race. Since many House races are uncompetitive, this measure is more valuable as an indicator of partisan sentiment than as a precise predictor of how many seats a party will win. But it’s still possible to compare the total number of Republican and Democratic votes cast with preelection polling estimates.
On the generic House ballot, the Democratic advantage in polls was nearly 9 percentage points, according to the RealClearPolitics polling average. As of Nov. 5, the House vote showed a Democratic lead of about 12 percentage points. The New York Times expects that advantage to tick up to 13 points when late-counting West Coast states finalize their tallies.
If the average error across all types of races ends up around 4 points, it would be larger than the error for similar races in the midterm elections of 2022 and 2018, as documented by the American Association for Public Opinion Research.
A 4-point average error would be a little larger than the state polling errors in the presidential and Senate contests in 2024, and on par with errors in the governors’ races that year. It would be roughly in line with state-level presidential polling errors in 2020, when surveys overstated Joe Biden’s margin by about the same amount.
It’s way too early to identify the source or sources of these errors. It takes time to compile critical data on who actually turned out to vote.
Panel surveys and turnout data will give us a better understanding of how much of the outcome was due to changes in vote choice versus changes in who turned out – and whether preelection polling adequately captured both of these dynamics.
Pollsters have worked hard over the past several election cycles to ensure that Republican voters are adequately represented in their samples. Adjustments based on party affiliation or past vote can improve accuracy, but their effectiveness depends on how these adjustments are made. One question for further analysis is whether weighting procedures and likely voter models adequately allowed for differences between the 2024 and 2026 electorates. (It also bears mentioning that 2026 brought several unique challenges for election polling.)
Preelection polling this year accurately depicted the public’s dissatisfaction with national conditions and where Americans placed the blame. It revealed that Democrats were highly motivated to vote, as well as dissatisfaction among parts of Trump’s 2024 electoral coalition. In the coming weeks and months, further analysis will help us better understand why the election unfolded the way it did and hopefully reveal why polling understated the forces that brought Democrats back into power in Congress and in many states.
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Scott Keeter is a senior survey advisor at Pew Research Center.
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ABOUT PEW RESEARCH CENTER Pew Research Center is a nonpartisan, nonadvocacy fact tank that informs the public about the issues, attitudes and trends shaping the world. It does not take policy positions. The Center conducts public opinion polling, demographic research, computational social science research and other data-driven research. Pew Research Center is a subsidiary of The Pew Charitable Trusts, its primary funder.
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