Most House maps are skewed to benefit Republicans

The difference between the Republican Party's share of a state's current House seats and the party's average share of that state's vote in recent statewide elections, among states with at least five seats

Statewide elections used in the average include the 2016, 2020, and 2024 presidential elections, as well as the state's most recent Senate election and gubernatorial election. Special elections are excluded. For states with ranked choice voting, the most recent election with a Republican and a Democrat in the final round of voting is used.

Vacant House seats are assigned to the party that most recently held them.
Chart: Andrew ManganSource: Dave Leip's Atlas of U.S. Presidential Elections; House of RepresentativesCreated with Datawrapper