Party leaders in Washington had so written off the idea of retaking the majority that a “Majority Project” launched last fall was aimed at elections in 2022 — after the next round of congressional redistricting. Trump’s rise to presumptive GOP nominee sparked a scramble in recent months to recruit Democratic candidates, even in some Republican-leaning districts.

“Donald Trump has been our best recruiting tool,” said Rep. Cheri Bustos (D-Ill.), who helps the party woo new House candidates.

Democratic consultants think that Trump’s rise has, broadly speaking, tilted the House battlefield in their favor by firming up candidates’ chances in battleground districts, allowing resources to be focused on more marginal seats. Trump, they say, has accelerated the party’s “demographic pivot” into more affluent, better educated, suburban districts. But there are gaping holes that could cost them gains.

“It’s unlikely that Democrats win back the House, but we can’t completely rule it out,” said Nathan Gonzales, editor of the Rothenberg & Gonzales political report. “Donald Trump puts enough volatility into the national political environment that we have to keep an open mind to lots of different scenarios.”