Representative Ken Calvert, a Republican who has served more than three decades in the House, is in a rematch with Democrat Will Rollins, who came close to beating him in 2022 in the Palm Springs-based district. Mr. Rollins is casting himself as a fresh face who is willing to work across the aisle.

LOS ANGELES - California is a key congressional battleground. A string of U.S. House races will determine which party controls the chamber next year. There are at least six swing districts in the state,