“If the Democrats control the House in 2024, it’s probably because four or five of these districts flip,” said Christian Grose, a political science professor at USC and the lead pollster. “It truly is so close that everything on the margins can make a difference.”

The poll offers a rare glimpse into battleground races across California, which aren’t often polled. And it did find one major advantage for Democrats: The party’s voters tend to be much more excited than their Republican counterparts about the House candidates on the ballot. Grose said that enthusiasm, coupled with higher turnout in a presidential election, could help the party flip seats in the Central Valley and Orange County suburbs.

That said, he noted most Republican incumbents in purple districts are polling far better than former President Donald Trump and Republican Senate candidate Steve Garvey. Grose said that suggests Republicans could offset the momentum Democrats are enjoying with Kamala Harris at the top of the ticket by convincing voters to cast split ballots.

— Democrat George Whitesides is leading Republican incumbent Mike Garcia by slightly more than one percentage point, 44 to 43 percent. The district, CA-27 (Santa Clarita and northern Los Angeles County), voted overwhelmingly for Biden in 2020, but Garcia has shown “resilience” and tends to outperform the rest of the Republican ticket in his district, Grose said.

— Democrat Derek Tran is leading Republican incumbent Michelle Steel by nearly two points, 45 to 43 percent. The suburban Orange County district, CA-45, is deeply purple, but Grose said Steel has typically outperformed GOP registration.

— In the Central Valley, Democrat Rudy Salas is four points ahead of Republican incumbent David Valadao, the largest margin of any swing-seat challenger. Salas leads 43 to 39 percent in CA-22 (Bakersfield and Kern County). One district over, Democrat Adam Gray leads Republican incumbent John Duarte by two points, roughly 44 to 42 percent in CA-13 (Merced County). Grose cautioned that both of their leads fall within the poll’s 6 percent margin of error for their districts. Grose noted that the rural Central Valley is notoriously difficult to poll due to low voter engagement.