von Wilpert advances, averting all-Republican race for Issa seat

Marni von Wilpert’s second-place finish in California’s 48th Congressional District primary kept Democrats from being shut out of the November ballot and prevented the seat from turning into an all-Republican runoff. In California’s top-two system, the two highest vote-getters advance regardless of party, and early returns showed Republican Jim Desmond leading the field with von Wilpert in second, ahead of Democrat Ammar Campa-Najjar.

The result mattered because the district, now open after Rep. Darrell Issa said in March 2026 that he would not seek reelection, had become one of the state’s most closely watched House contests. The race is the latest test of whether Democrats can translate a voter-registration edge of about 4 percentage points into an actual victory in November. Desmond, a San Diego County supervisor and former mayor of San Marcos, entered the primary with President Donald Trump’s endorsement. Von Wilpert, a San Diego City Council member since 2020, brought a record that included work as a civil prosecutor and service in the Peace Corps.

The district itself was redrawn under Proposition 50, approved by California voters on Nov. 5, 2025, and now straddles Riverside and San Diego counties. Its boundaries run through places such as Vista, San Marcos, Palm Springs and Temecula, making the seat a blend of suburban San Diego politics and Inland Empire competition. Democrats targeted the district as part of the broader push to reclaim House control, and CA-48 became one of the seats that party strategists believed could be made more favorable under the new map.

The primary field underscored how much was at stake. Nine Democrats, two Republicans and one independent competed for the open seat, but the top-two format meant the party with the most candidates could still be locked out if its vote split too evenly. A May 2026 Tulchin Research poll had already suggested the contours of the race, showing von Wilpert emerging as the leading Democratic candidate while Desmond consolidated Republican support. By advancing, von Wilpert ensured that November 3, 2026, will feature a direct partisan contest, not a Republican-on-Republican fight for a district Democrats hope the new lines can help them flip.