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Dear Readers: Today’s contributors, Debra Leiter, Mary Stegmaier, and Michael Lewis-Beck, are all veteran political scientists who have explored the concept of “citizen forecasting,” the idea that the public (through polling) can help forecast elections through their opinions on who they believe will win. Leiter and Lewis-Beck wrote about this concept in the Crystal Ball last cycle. Today, they discuss the results of an April poll asking U.S. adults who they believe will win the House and the Senate majorities next year, with the public leaning toward Republicans in both chambers as the cycle gets underway. — The Editors |
KEY POINTS FROM THIS ARTICLE
— Asking citizens themselves to predict what will happen in elections is an emerging tool in forecasting elections.
— Despite a usual trend of midterm seat loss for the presidential party, a survey of U.S. adults from April suggested the public was likelier to believe Republicans would win majorities in both chambers next year.
— This comes despite more respondents believing that President Trump’s approval rating will decline and the economy will worsen in the future.
The public’s early assessment of 2026
Midterm elections to the United States Congress are often viewed as referenda on the performance of the president’s party, with voters rewarding or punishing on key issues accordingly. More specifically, the “iron law” in these contests, as noted by Charles Tien and Michael Lewis-Beck, “foretells the ruling party would experience a net loss” of seats. Since the end of World War II, presidential party seat loss has been common in midterms, although the loss happens more consistently in the House than in the Senate. Both voters and political strategists thus often view these elections not as a question of who will win, but of just how big the losses for the incumbent party will be.
The current partisan composition of the U.S. government, with a Republican president and slim Republican majorities in both the House and Senate, point to the near certainty of midterm congressional loss for the Republicans in 2026. Indeed, two recent publications in the Crystal Ball point to the Democrats retaking the House, according to the House race ratings and the generic ballot. The practical question, in terms of the transfer of political power, becomes “Will the incumbent party lose majority control of the chambers?” Herein we examine how Americans are currently answering that question for the House and the Senate in national scientific public opinion surveys recently fielded by Verasight in April 2025. The findings suggest that voters have clear and consistent opinions about which party will control Congress. Moreover, the predictions, as they stand, indicate that this “iron law” of incumbent party loss might be broken, with the Republicans keeping control of one, if not both, chambers. Below, we unfold the evidence, beginning with the quality of the survey, then go on to consider majority forecasts for the House and the Senate. Finally, we draw conclusions about the degree of accuracy these citizen forecasts display.
The survey data
In its annual Midwest Political Science Omnibus Survey, fielded from April 9-15, 2025, the polling firm Verasight conducted three sample modules of high scientific quality, each with 1,000 U.S. adult respondents. Respondents came from the Verasight Community, individuals randomly recruited by addresses, text messages, and online, subject to multi-step authentication. Further, the data were weighted to match key socio-demographics, including age, race/ethnicity, sex, income, education, region, metropolitan status, and partisanship. The margin of error, employing the classical random sampling formula, is +/- 3.5% for the Elections module, which we utilized for the tables and results below.
The central survey questions we analyze ask respondents to predict which party will achieve a majority in the House and in the Senate. The specific wording, for the House, is as follows:
“Thinking about the midterm elections in 2026, which party do you think will win control of the U.S. House of Representatives?” (Response options: Democrats will win a large majority, Democrats will win a slim majority, Republicans will win a slim majority, Republicans will win a large majority). The same question was asked for the Senate.
Forecasting theory: Voter intentions versus voter expectations
A popular approach to forecasting U.S. election outcomes involves examination of voter intention questions asked in systematic polling, such as “Who will you vote for in the upcoming election?” Of course, there are other scientific approaches, including election markets and voter expectations. (See the panoply of approaches considered in the recent PS collection of forecasting articles on the 2024 U.S. elections.) Rather than voter intentions, we focus on voter expectations, which ask “Who do you think will win in the upcoming election?” This approach, called citizen forecasting (CF), has a history of successfully predicting presidential election outcomes. Citizen forecasting was applied to the 2024 U.S. presidential election with mixed results, demonstrating the promise and challenge of this approach; however, beyond its accuracy, it provides us insight into what voters think will happen. At the legislative level, its application is scarce in the United States, but it has been used in the United Kingdom, where it has proved highly predictive at the constituency level. For the upcoming 2026 U.S. midterm election, we utilize CF to project the aggregate outcome well in advance of the election. Specifically, we ask respondents which party (Republican or Democratic), they think will win majority control of the chamber.
Results: Which party will take control?
Looking at voter expectations for the House, the results are especially clear (see Table 1a). The respondents foresee a Republican victory in the House, with 58% (40% + 18%) predicting a majority for the White House party, in contrast to 42% (31% + 11%) for the Democrats. Moreover, when a 95% confidence interval is placed around these point estimates using the margin of error of +/- 3.5 points, we observe that the Republican expectation never falls below 50% [54.5%, 61.5%], while the Democratic expectation never rises to 50%, [38.5%, 45.5%]. The House, then, would seem likely to stay Republican, according to these numbers.
What about the Senate? (see Table 1b). The results are much the same. The respondents foresee a Republican win for the Senate, with 57% (38% + 19%) calling a majority for the White House party, in contrast to 43% (31% + 12%) for the Democrats. With respect to 95% confidence intervals around the point estimates, we observe that the Republican expectation, like in the House, remains above the 50% mark [53.5%, 60.5%]. For the Democrats, the expectation remains below 50% [39.5%, 46.5%].
In sum, if things stand as they are by November 2026, this polling points to Republicans holding on to both chambers. However, quite a lot of the electoral game is still left to play in the next year and a half. As the 2024 election showed, fundamentals, including presidential approval and economic outlook, play a key role in shaping electoral outcomes. We discuss such possibilities below.
Table 1a: Forecast for the House majority
Thinking about the midterm elections in 2026, which party do you think will win control of the US House of Representatives?
Table 1b: Forecast for the Senate majority
Thinking about the midterm elections in 2026, which party do you think will win control of the U.S. Senate?
Discussion: Will the apparent Republican advantage change?
Of course, down the road, the forecast of Republican dominance could change. For one, at this point in time, voters may not generally be familiar with the elemental facts of political party composition in Congress, including the affiliation of their own Representative. Table 2 speaks to this question.
Table 2: Respondent knowledge of the political party of the district’s House member
What is the political party of your district’s member of the U.S. House of Representatives?
We observe that most respondents are able to assign a partisan label to their representative. Further, in the aggregate, they are somewhat more likely to select Republican over Democrat (39% – 34%), which jibes with the facts, namely that the House presently has a narrow Republican majority. This suggests a noteworthy level of relevant knowledge, at least collectively, which tends to rule out the possibility that the Republican “guesses” in Tables 1a and 1b are random, driven by lack of information.
A strong general belief about American politics, backed up by extensive literature, argues that the strength of the economy is critical for maintaining incumbent party support. Certainly the economy appeared to play a significant role in the 2024 presidential contest. Perhaps the perception of the Republican advantage is driven by voters seeing a brighter economic future under a Republican administration? Table 3, on economic optimism, speaks to this question.
Table 3: Respondent optimism about next year’s economy
How optimistic do you feel about the US economy in the next year?
We observe that respondents actually are not more optimistic about the future direction of the economy. Instead, they are more pessimistic. That is, while 35% show some degree of optimism, fully 46% show some degree of pessimism. Hence, a rosy picture of the economy does not help explain why these voters expect the midterm “iron law” to be broken.
Perhaps instead the Republicans’ advantage is driven by presidential approval. If, indeed, midterm elections are referenda on the incumbent party, then we would expect that expectations about presidential approval would impact voter expectations for the 2026 election. Yet the puzzle does not become clearer when we examine expectations about presidential approval, which offers a more global assessment of incumbency performance, including economic as well as non-economic issues (see Table 4).
Table 4: Respondent expectations about presidential approval next year
What do you think will happen to Donald Trump’s approval ratings in the next year?
Respondents are much more likely to think Trump’s approval will decrease in the next year (50%), rather than increase (32%). Thus, voter confidence that Republican control of Congress will be retained at midterm time cannot be accounted for by an expected rise in his popularity. Voters may be familiar with the fundamentals of politics, but it does not mean that they are necessarily willing to translate those estimations into shaping estimations of victory in 2026. These results point to the challenges faced by the Democratic Party today; even with low levels of optimism about the economy, and expectations about declines in presidential approval, voters seem skeptical that they can translate these challenges for the incumbents into electoral success. In fact, it’s possible that the challenges faced by Democrats help to explain these findings: On both the House and Senate control questions, Democratic respondents were a little less likely to predict their own side would win majorities than Republicans were. However, self-described independents were also likelier to favor Republicans winning both chambers, with percentages similar to the overall findings for both predicted House and Senate control (these specific crosstabs can be found at the Verasight link).
Conclusion
The voting public, as of this spring, appears to expect that the Republicans will likely remain in control of both chambers of Congress in the 2026 midterm elections. These views are held by respondents who, at least collectively, know the current political composition of Congress. They believe that Republicans will maintain their majority, despite their perceptions of a rocky economy road ahead, led by a president with faltering in-office performance ratings. Moreover, they hold this belief in Republican congressional control in the face of the rule of midterm loss for the incumbent party, which points to a return of Democratic control.
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Debra Leiter is Associate Professor of Political Science in the Department of Political Science and Philosophy at the University of Missouri-Kansas City and Secretary- Treasurer of the Political Forecasting Group. An award-winning researcher and teacher, her forecasting research has focused on networks and citizen forecasting and forecasting pedagogy. Mary Stegmaier is Vice Provost for International Programs and Professor of Government and Public Affairs at the University of Missouri. In addition to her publications on elections, voting behavior, and forecasting, she and Philippe Mongrain guest edited the PS: Political Science & Politics special issue on “Forecasting the 2024 US Elections.” She currently serves as an Associate Editor of the International Journal of Forecasting. Michael S. Lewis-Beck, F. Wendell Miller Distinguished Professor of Political Science at the University of Iowa, has authored or co-authored over 340 articles and books, including Economics and Elections, The American Voter Revisited, French Presidential Elections, Forecasting Elections, The Danish Voter and Applied Regression. He has served as Editor of the American Journal of Political Science and of the Sage QASS series (the green monographs) in quantitative methods. He currently serves as an Associate Editor of French Politics. |