This story is part of a series from Public Matters, a reporting project in collaboration with KPBS. Read more stories here.
Ahead of the 2026 midterm elections, money is pouring into American politics at levels never seen before.
Here in San Diego County, millions of dollars have already been spent on races and ballot measures countywide. KPBS and Voice of San Diego poured over campaign finance filings from several different reporting agencies to compile a list of the biggest spenders and donors impacting San Diego regional politics.
Our top spenders – who spent the most on campaigns – were the California Democratic Party, the “Yes on B” campaign for Measure B, and a super PAC called California Leads. The top donors – who contributed the most to campaigns – included the Laborers International Union of North America Local 89, the California Association of Realtors, and Sharp HealthCare.
Some of the donations and spending came during the primary election. For example, the California Association of Realtors dropped hundreds of thousands of dollars opposing a failed second home tax while Sharp HealthCare funded a committee backing a successful North County ballot measure involving the company and Tri-City Healthcare District.
Our review focused on spending from 2026 to avoid incorporating races that played out in the prior year but the top donors list incorporates donations made in the lead-up to this year’s campaign to committees or candidates that are spending in 2026. We also focused solely on spending in San Diego County and didn’t review federal campaign data.
Our tallies only include spending and donations that have been reported as of the Oct. 22 filing deadline, which required reports on spending and donations made before Oct. 17. Unpaid bills were not included in spending totals. Campaigns and committees will spend more money between this date and the election date, and are not required to disclose this last period’s spending until February 2027.
KBPS used artificial intelligence tools to help build software to collect and analyze campaign filings. KPBS and Voice checked original documents to confirm dollar figures, and no data was generated by AI.
San Diego’s Political Power Players: Top Spenders and Donors
Editor’s note: Irwin Jacobs is a financial supporter of KPBS. The KPBS news operation maintains editorial independence from KPBS executives, SDSU and corporate underwriters and donors. Jacobs and Mel Katz are also donors to Voice of San Diego.