In a forecasting special issue of PS: Political Science & Politics for the US midterm elections, all forecasters predict that the Democrats will capture the House of Representatives, but are split on who will emerge victorious in the Senate.
Published by Cambridge University Press on behalf of the American Political Science Association (APSA), the special issue includes 17 studies showcasing a range of forecasting approaches and methodologies, from traditional political economy models to controversial betting markets and AI 'synthetic personas'.
The US Congressional Midterm elections take place on 3 November 2026. They will see all 435 seats in the House of Representatives and 35 Senate seats contested, with control of Congress potentially decided by a handful of highly competitive races.
More broadly, the collection explores how political dynamics are reshaping both elections and the tools used to understand them, and asks whether traditional models can still make accurate predictions in a time of heightened polarisation and political change.
Dr John Kenny, co-Guest Editor of the special issue from the University of Mannheim and University of Southampton, said: "Midterm elections have historically seen the president's party lose support, driven by economic concerns and falling approval ratings.
"But the political landscape in 2026 is somewhat atypical. Increased polarisation and widespread redistricting have introduced new uncertainties, creating challenges for predicting whether this election will follow established patterns or whether it will mark a significant shift in American politics."
Predictions for 2026
Many of the studies in the special issue have made predictions on the outcomes of the midterm elections taking place on 3 November 2026.
The verdict was unanimous on a Democrat victory in the House race, with 12 out of 12 predictions in their favour.
Predictions for the Senate race were less clear. Some forecasts are calling it for the Republicans and others are predicting a Democrat victory. All are expecting a close and contentious electoral victory.
Dr Debra Leiter, co-Guest Editor from the University of Missouri-Kansas City, said: "With such a narrow Republican majority, Democrats require only modest gains to retake the House, but the Senate will be harder to flip due to the number of Republican-held seats considered secure. Record breaking spending, open-seat contests created by a wave of retirements, and unexpected candidate choices are expected to increase competitiveness across key battleground states.
"Coupled with the unique circumstances of the 2026 election, it's a tough one to call. Will we see a return to the fundamentals of American election forecasting, or will it prove a challenge to the widespread beliefs about American electoral behaviour?"
Highlighted papers
Roberto Cerina. 'Polling Without People: Can Silicon Samples of CASM-Inspired LLM Personae Mimic Human Respondents in Pre-Election Polling?'
