The first poll in the general election race for California’s 48th Congressional District shows Democrat San Diego City Councilmember Marni von Wilpert in a statistical tie with Republican County Supervisor Jim Desmond.
Von Wilpert came in second to Desmond in the June top-two primary among a crowded field of Democrats to advance to the general election.
The poll was conducted by Lake Research Partners, a Democratic polling and research firm, and shared by the von Wilpert campaign on Monday. It has von Wilpert leading by two percentage points over Desmond, but within the margin of error.
Among 500 likely voters, 48% chose von Wilpert, 46% chose Desmond, and 6% remain undecided. But 38% said they “strongly support” Desmond, while 36% said the same of von Wilpert.
The margin of error for the poll was 4.4%, meaning the race is essentially tied at the outset of the general election campaign, according to UCSD political science professor Thad Kousser.
“So that means that their best guess is that Marni von Wilpert is leading 48 to 46,” Kousser said. “But it could be that she's leading 52 to 42, or it could be that Jim Desmond is leading by two percentage points.”
Kousser said a poll of just 500 people introduces a higher possibility of error, and the way surveys are conducted also creates a chance for inaccurate results. “Polls could also be wrong, and much more often are wrong due to sampling bias,” Kousser said. “So it may be that, who wants to answer a survey about politics in the summer in San Diego?”
California’s 48th District is one of five congressional districts the state legislature targeted with Proposition 50, which redrew the lines of the state’s congressional map to favor Democrats.
The seat could be one of just a few that will decide who controls the U.S. House of Representatives in 2027 and 2028.
The von Wilpert campaign shared the poll in a press release on Monday. They continued to try to tie Desmond to President Trump.
“MAGA Jim Desmond is already losing and that’s even before voters know the full story of his corrupt, costly pro-Trump agenda,” Campaign Manager Jacob Ostacher said in the press release. “Jim Desmond has never met a Trump policy he wouldn't rubber stamp or a special interest he wouldn't cash in on, and Southern California families are paying the price – at the pharmacy, the pump and the grocery store.”
But the Desmond campaign had a more optimistic view of what the poll meant for them. “Jim Desmond has a strong record of delivering results and providing proven commonsense leadership which is why even the Democrats’ own poll shows this race is within the margin of error,” campaign consultant Sam Oh said in a statement to KPBS. “As voters learn more about Marni von Wilpert’s record of supporting higher utility costs, we’re confident they’ll choose Jim Desmond’s proven leadership over her costly agenda.”
Republican and current incumbent Darrell Issa chose to retire rather than run for reelection in the redrawn 48th District. He endorsed Desmond to succeed him in March.
Lake Research Partners is a polling and research firm founded by Democratic Party strategist Celinda Lake. The firm works to advance a “progressive, inclusive future,” according to its website.
