Your guide to the California Congressional District 48 race: A battleground that could reshape Congress

The race for California’s 48th Congressional District has become one of the most closely watched House contests in the state, following the sudden retirement of longtime Republican incumbent Darrell Issa.

The district, which spans parts of San Diego and Riverside counties, had long been considered firmly Republican territory. But a new map adopted under Proposition 50 dramatically changed the political calculus, turning what had been a GOP stronghold into a district that now slightly favors Democrats. With Republicans hanging on to an extremely slim majority in Congress, a win in District 48 could be just what Democrats need to regain control over the U.S. House of Representatives.

That outcome would spell trouble for President Trump, who already has gotten involved in the race. Following Issa’s announcement in March, Trump threw his support behind Republican Jim Desmond, who has solidified himself as the conservative front-runner.

The Democratic field remains crowded, and party infighting threatens to split the vote between two leading candidates: San Diego City Councilmember Marni von Wilpert and three-time congressional candidate Ammar Campa-Najjar of Chula Vista. At the California Democratic Party convention in February, von Wilpert won a majority of delegates’ votes — just short of the 60% threshold for an official party endorsement — while Campa-Najjar won 18%.

Meanwhile, Palm Springs Democrat Brandon Riker is gaining momentum outside of establishment corridors. His campaign war chest is larger than all other candidates’ by hundreds of thousands of dollars.

California

Voter guide to the 2026 California primary election

California’s primary election takes place on June 2. Learn about L.A.’s city and county races and others for state offices.

May 1, 2026

Major population centers include cities such as Escondido, Vista and San Marcos in San Diego County, while the district also extends into inland to Temecula, Hemet and Palm Springs in Riverside County.

The district reflects a mix of suburban commuter communities and is located near major military installations like Marine Corps Base Camp Pendleton and the Naval Weapons Station in Fallbrook.

Ammar Campa-Najjar, a U.S. Naval reserve officer, former U.S. Labor Department official and three-time congressional candidate, is one of the best-known Democrats in the race. A strong fundraiser, he previously ran against Issa and other Republican incumbents and has compiled a long list of establishment endorsements. His campaign has focused on economic opportunity, protecting democracy and expanding healthcare access. Campa-Najjar has drawn recent criticism for breaking Pentagon rules barring reservists from using uniformed photos as “primary graphic representation” in campaign material.

Jim Desmond, a San Diego County supervisor and former commercial airline pilot, entered the race with Issa’s endorsement and quickly emerged as the leading Republican contender when Trump backed his campaign in April. Desmond has emphasized conservative priorities including border security, cutting federal spending and addressing inflation.

Brandon Riker, a Palm Springs entrepreneur and economist, has emerged as the best-funded Democrat in the field and has financed much of his own campaign. A campaign organizer for Barack Obama’s 2008 presidential bid, according to his campaign website, Riker has focused on affordability and economic development, endorsing a higher minimum wage, capping social security taxes for low-income earners and expanding healthcare.

Marni von Wilpert, a San Diego City Council member and workers’ rights attorney, has positioned herself as a pragmatic Democrat focused on taking on corruption, bolstering workers’ rights and holding federal immigration agents accountable for constitutional abuses. She says her experience flipping a city council seat from Republican to Democrat demonstrates an ability to win in competitive districts.

Desmond has made his alignment with the Trump administration clear in recent weeks, telling the San Diego Union-Tribune in April that he supports many of the president’s policies, including his effort to reverse birthright citizenship.

“I support the fact that he shut down the border. I support the fact that he’s trying to lower taxes. I support the fact that somebody had to step up and take on Iran,” Desmond said.

His loyalty quickly was rewarded with a formal endorsement from Trump in April. In a Truth Social post, Trump promised supporters that Desmond will “Ensure PEACE THROUGH STRENGTH” when it comes to military decisions and praised the candidate’s economic policy and his efforts to “Keep our Border SECURE [and] Stop Migrant Crime.”

The Democratic candidates all have criticized Trump, though with varying degrees of emphasis.

Campa-Najjar framed his concerns broadly around national unity, warning that the administration’s rhetoric has “fueled division at a time when Americans need unity and solutions.”

Riker argued Democrats must move beyond simply opposing Trump, saying the party should focus on advancing policies like student debt relief, expanding the Affordable Care Act and protecting reproductive rights.

Von Wilpert has positioned herself as the anti-Trump candidate, promising to “make Washington work for working families again — not the wealthy few.”

“President Trump has failed disastrously on the core promises he made to the American people,” von Wilpert said, pointing to the administration’s “attacks on health care and food assistance,” pro-billionaire economic policies and “reckless trade wars that raise prices on working people.”

Campa-Najjar grounded his position in both personal experience and criticism of federal policy. He said “federal agents are in our neighborhoods terrorizing families” and called for comprehensive immigration reform that includes “humane border solutions,” improved ports of entry and pathways to citizenship for longtime residents.

“Under the Trump administration, the Department of Homeland Security has been politicized, turning immigration enforcement into a blunt instrument of power rather than a fair, law-based system,” he said.

Desmond is a border security hardliner who supports Trump’s deportation policies. He has argued that stronger border security and tougher immigration controls are necessary to maintain public safety and economic stability.

“Weak enforcement and lack of accountability have let this crisis grow. That ends when I get to Congress,” he wrote on social media in a post about cross-border human trafficking.

Riker sharply criticized the Trump administration’s enforcement practices, arguing the federal government has overreached. He called for reforms that “create realistic pathways to citizenship” while also “securing the border sensibly” and expanding legal immigration channels.

“Detaining and deporting noncriminal immigrants is wrong and the Trump administration has gone too far and have no clear limits and accountability,” he said. “ICE agents are acting in ways that terrorize people on the streets and are invoking fear in families and our communities.”

Von Wilpert framed her stance as balancing enforcement with civil rights protection, pointing to legislation she passed as a council member opposing “excessive” tactics by Immigration and Customs Enforcement.

“We absolutely need a functioning immigration system that includes taking violent offenders off our streets to keep our communities safe,” she said. “But mass detention, tearing families apart and fatal violence in our streets isn’t law enforcement, it’s chaos and unconstitutional.”

Drawing on his service as a Naval reservist, Campa-Najjar takes a cautious approach to military engagement. “War is never an abstract policy debate. It is personal. Our neighbors deploy. Our families sacrifice,” he said.

Campa-Najjar argues military force should be a last resort and must be authorized by Congress, while warning against unilateral actions that “escalate conflict without accountability.” Instead, he calls for exhausting diplomacy first and ensuring any intervention is guided by moral purpose.

Desmond repeatedly has signaled his support for Trump’s war in Iran and framed spikes in gas prices as a temporary by-product of international security.

“No pain, no gain. It’s unfortunate the oil prices are going up, but I do believe this is a spike,” he said in an appearance on the conservative talk show “America Sunrise.” Desmond added: “President Trump is right. Once we are able to get rid of their nuclear capabilities, oil prices will come down again.”

Riker also has called for caution, stressing the importance of international law and congressional authority in decisions to deploy military force. He has raised concerns about recent U.S. military actions abroad, arguing they highlight the need for clearer standards and accountability in foreign policy decisions.

Von Wilpert has strongly criticized the prospect of unilateral military action, particularly regarding Iran. While acknowledging the threat posed by Iran’s government, she called on Congress in March to exercise its power to block Trump from carrying out an unconstitutional war.