MAP: See where a blue wave would swipe the most GOP seats

"Flashback: The 2018 midterms saw a 6.5 percentage point swing in Democrats' favor compared to President Trump's 2016 margins, giving them 41 new seats for a 235 -199 majority, according to the Cook Political Report. A similar shift in 2026 would translate into 12additional Democratic seats, giving them a 227-208 majority, according to the data, which includes redistricted maps, according to The Downballot and Sabato's Crystal Ball."

"Zoom out: Democrats are banking that the electorate will look a lot less Trumpy when the president's name is not on the ballot. Their voters, Democrats argue, are highly motivated and engaged when Trump is in office. Zoom in: Presidential performance in a congressional district doesn't guarantee a predetermined outcome, but in the Trump era, the number of crossover districts is at a historic low."

"Thirteen House Democrats prevailed in seats that Trump carried in 2024. A total of three Republicans held on in Harris districts. In 2008, after President Obama's first election, there were 83 crossover districts. Two of the best lawmakers at convincing voters to split their ticket - Rep. Don Bacon (R-Neb.), who won in a Harris +4.6 district, and Rep. Jared Golden (D-Maine), who won in a Trump +9 district - are both retiring."

The universe of competitive House seats is historically small, so even an unambiguous national move toward the Democrats would produce only a relatively narrow Democratic majority. A 6.5-point Democratic swing like 2018 translated to 41 seats then; an identical swing in 2026 would be worth roughly 12 additional Democratic seats for about a 227-208 majority under current redistricted maps. If GOP House candidates perform about 1% better than Trump did, Republicans could instead gain roughly 12 seats and reach about a 232-204 majority. Crossover districts have declined sharply in the Trump era, several effective ticket-splitting lawmakers are retiring, and recent tit-for-tat redistricting appears to have netted Republicans additional seats while Democrats push changes in Virginia and Republicans seek parity in Florida.

Read at Axios