Marni von Wilpert (D) and Jim Desmond (R) are running in the general election for California's 48th Congressional District on November 3, 2026. Incumbent Darrell Issa (R) is retiring from public office.

Times of San Diego's Andrew Keatts wrote the election "is among the most-watched contests in the nation, and could determine partisan control of the House."

This district was redrawn prior to the election due to Proposition 50. The old district voted for President Donald Trump (R) over Kamala Harris (D) in the 2024 presidential election 56% to 41%. Harris would have won the new district 50% to 47%, an 18-point shift toward Democrats. In the June 2 primary, Desmond and the other Republican candidate on the ballot, Kevin O'Neil, combined for 48% of the vote, while nine Democratic candidates combined for 51% of the vote. Amalia Martinez, vice president of communications for the Escondido Democratic Club, said that despite the district's shift toward Democrats, Desmond "appears more approachable, less polarizing, and he has given grants to different areas, and people know him for that, so it’s going to be tough."

Von Wilpert is a member of the San Diego City Council. She is campaigning in opposition to Trump's policies, and said, "whether it's stopping [ICE] from raiding our communities ... undoing the costly tariffs ... restoring affordable health care. I will stand up for our community against Donald Trump. And I'll do it every day." Von Wilpert is also campaigning on reducing the cost of housing, and her campaign website says she "will cut red tape and make it easier to build more affordable housing to make sure people can live closer to where they work."

Desmond is a member of the San Diego County Board of Supervisors and a former mayor of San Marcos. Desmond is campaigning on his local government experience, saying, "Decades of local service as mayor and county supervisor have given me a deep understanding of local, state and federal issues ... I will bring knowledge of local issues to Congress to fight for Southern California and deliver real results for families in the 48th district." Desmond is also campaigning on affordability, and his campaign website says he supports "lowering taxes, reducing overregulation, and curbing out-of-control costs that are driving seniors and families out of the state."

The outcome of this race will affect the partisan balance of the U.S. House of Representatives in the 120th Congress. All 435 U.S. House districts are up for election.

Currently, Republicans have a 219-212 majority with four vacancies in the chamber. To read more about the U.S. House elections taking place this year, click here.