The closing days of the contest for California‘s 48th Congressional District have been dominated by an extraordinary spike in advertising and independent spending. In a tight Democratic primary to replace retiring Representative Darrell Issa, certain groups have concentrated large sums of money on both promoting and opposing specific candidates. The most visible effect has been on Ammar Campa-Najjar, who has attracted more negative independent expenditures than any other candidate in the field. Observers say this late surge may reshape who advances from Tuesday’s primary.
Political committees and newly formed super PACs have funneled money into the race in strategies designed to influence the outcome without direct coordination with campaigns. The spending pattern highlights how outside groups can use legal loopholes to reflect a campaign’s messaging while remaining technically independent, and it raises familiar concerns about transparency when donors remain undisclosed until after ballots are counted.
Money flows and major players
Several organizations have been key actors in the closing weeks. The Democratic Majority for Israel has spent roughly $2 million opposing Campa-Najjar, including an initial half-million dollar outlay before any independent committee publicly formed to support him. That opposition is far larger than the PAC’s expenditures against other candidates nationwide this year. At the same time, San Diego Councilmember Marni von Wilpert has benefited from over $2.16 million in independent expenditures backing her, according to filings available through Thursday, May 28.
Tactics: support that looks like opposition and vice versa
Some groups have combined endorsements of one candidate with attacks on another. For example, Project 218 ran a campaign that both praised von Wilpert and criticized Campa-Najjar, spending about $900,000 on that dual-purpose ad effort. Such moves often use a technique called redboxing, where independent ads mirror a candidate’s public themes and language without formal coordination. Campaigns benefit from the echo, while outside groups maintain legal separation.
Counter-spending and aligned super PACs
Other super PACs have emerged to counterbalance those attacks. Serving CA—a committee convened to support Campa-Najjar—listed backers in its first filing that included Qualcomm co-founder Irwin Jacobs and an organization largely funded by members of the Bezos family. Serving CA has spent more than $600,000 opposing von Wilpert and over $200,000 in direct support of Campa-Najjar, bringing his total in independent expenditures to roughly $890,000. Still, those supporting him have not matched the volume of spending targeted at him.
New entrants and opaque funding
A newly formed super PAC, Veterans for Truth PAC, appeared at the end of April and has spent more than $630,000 aiming to keep Campa-Najjar out of the general election. The PAC’s activity to date consists almost entirely of opposition spending against him, and its funding sources are not publicly disclosed. Because of reporting cycles, the identity of donors behind many late-spending groups often remains hidden until after voters have made their choice.
Why late spikes happen
Money-in-politics experts say this pattern is common in competitive contests. Michael Beckel, director of money in politics reform at Issue One, notes that hotly contested districts attract late contributions from both super PACs and less-transparent organizations hoping to shape the legislative map. Such groups are legally required to file monthly disclosures, but filings created close to Election Day frequently won’t appear until after the ballots are cast, allowing backers to influence outcomes while delaying public scrutiny.
The strategic goal for many of these donors is clear: competitive primaries determine which party’s nominees will be in position to win general elections and, on a broader scale, influence who controls key committees and legislative priorities in Congress. In a district redrawn by Proposition 50 and now widely viewed as a pickup opportunity, the stakes for outside funders—and for the candidates being supported or targeted—have never been higher.
As voters approach Tuesday’s primary, additional spending is expected in the final days. Whether the flood of independent expenditures will be decisive remains uncertain, but the volume and timing of the outlays illustrate how modern campaigns are increasingly shaped by outside money and after-the-fact transparency rules. For residents of the 48th District, the result will determine which two names appear on the November ballot and which political forces will claim influence over the contest’s outcome.
