Harry Enten reveals Republicans' election history of outperforming what polls say will happen

CNN's Harry Enten.

A raft of polls four weeks out from the midterm elections paint the picture of a blue wave coming on November 3, but is that portrait just a mirage? CNN data guru Harry Enten revealed in a segment on Wednesday that polling in certain battleground states have a history of overestimating Democrats' performance in elections during the Trump era.

The polling Americans are seeing that suggests Republicans are set to lose control of the House and could lose control of the Senate could be significantly underestimating Republicans' chances if history is a guide. Enten walked viewers through that recent history, showing how on Election Day in 2024, Republicans, including Donald Trump, outperformed the polling data collected during the month of September in Iowa by nine points, Ohio by six points and Michigan by five points. 

Obviously, Trump was on the ticket as the main candidate in 2024, but the president has urged voters to behave as though he is on the ticket this year. Still, a similar trend showing Republicans outperforming the polling in key battleground states was apparent in 2018 as well, another year in which Trump wasn't officially on the ticket. Republicans in Iowa, Ohio and Michigan outperformed the results of September polls by six points, six points and eight points, respectively.

If the trend holds true again in 2026, what will it mean? Enten said even if Republicans over-perform in those states, some states, like Texas and Alaska, could go blue, and a likely outcome would be a 50-50 split in the Senate, meaning Republicans would still maintain the majority with JD Vance as the tie-breaking vote. Enten also pointed out that the prediction markets, like Kalshi, have not factored in this sort of historical trend line, with bettors putting their money on Democrats taking control in both chambers of Congress. 

Watch the full segment below: