A high-stakes congressional contest in Southern California is shaping up as a major test of Democratic redistricting strategy after a new survey revealed a remarkably narrow margin in a newly reconfigured battleground.
Republicans argue that California Governor Gavin Newsom’s redistricting push risks backfiring into a political liability, pointing to polling data showing Republican Jim Desmond trailing his Democratic opponent by only three percentage points despite an onslaught of millions of dollars in negative advertising.
The survey, conducted between October 17 and 20 by the polling firm The Tarrance Group and commissioned by Desmond’s campaign, found Democrat Marni von Wilpert leading Desmond 47% to 44% among 410 likely voters in California’s 48th Congressional District. The poll carries a margin of error of 4.9 percentage points.
The district spans parts of San Diego and Riverside counties and was altered during California’s 2025 redistricting process, converting what had previously been a Republican-leaning seat into a Democratic-leaning battleground. Longtime representative Darrell Issa, a Republican, is retiring, leaving an open seat that Democrats have targeted as a prime pickup opportunity.
National Republican Congressional Committee spokesman Christian Martinez argued that heavy Democratic spending has failed to secure the seat. He contended that voters are rejecting the Democratic record despite millions spent on opposition advertising, suggesting that the race could turn the governor’s redistricting efforts into a national embarrassment.
Desmond’s campaign reported that more than $7.5 million has been deployed against him since the beginning of September. Desmond, a San Diego County supervisor and former mayor of San Marcos, has anchored his platform on lowering taxes, cutting costs, and rolling back regulations. While he holds an endorsement from Donald Trump, Desmond has also worked to carve out distinct positions on specific issues.
“People have lived through years of failed California policies,” Desmond said, pointing to higher taxes and living costs. “They know what that looks like, and they’re ready for something different.”
At the same time, Governor Newsom faces persistent headwinds among key demographics in the area. The polling memo indicated that voters registered with no party preference view Newsom unfavorably by a 53% to 37% margin.
The financial footprint of the race is substantial. According to CalMatters, more than $6 million in independent expenditures has flooded the contest, with nearly all of that outside spending backing von Wilpert through entities such as the House Majority PAC and Democratic Majority for Israel. Desmond has drawn independent backing from Trump’s No Going Back PAC.
Fundraising figures show von Wilpert holding an advantage, having raised $4.5 million compared to Desmond’s $3 million.
Independent election handicappers continue to view the contest as competitive but lean in favor of the Democrats. The Cook Political Report rates the race as “Lean Democratic,” noting that the district carries a partisan voting index of D+2. Redistricting granted Democrats a three-percentage-point voter registration edge in the territory.
Von Wilpert, currently serving as a San Diego City Council member, has positioned herself as a mainstream Democrat with a proven track record in competitive electoral environments. Her campaign has focused heavily on economic affordability, support for Israel, and direct opposition to Trump’s policies.
