NORTHERN CALIFORNIA — Mike Thompson and Eric Jones advanced to the general election after finishing atop the June 2, 2026 top-two primary for California's 4th Congressional District. The primary ballot included six Republican candidates and one independent candidate.

California's top-two primary system allows the two candidates with the most votes to advance to the general election, regardless of their party affiliations. From 2016 through 2024, one Democrat and one Republican consistently advanced from every top-two primary in the 4th Congressional District. Redistricting altered the boundaries of the 4th Congressional District prior to the 2026 election cycle. The new 2026 district boundaries favor Democratic candidates by a narrower margin compared to the 2024 boundaries. As of June 2026, election forecasting models rated the 4th Congressional District general election as Solid/Safe Democratic. California Democrats adjusted congressional district boundaries to offset Republican redistricting efforts in Texas and other states.

Mike Thompson was first elected to the U.S. House of Representatives in 1998. He previously served eight years in the California State Senate and currently serves on the House Ways and Means Committee. The Democratic Party of California endorsed Thompson for re-election.

Eric Jones is a 35-year-old former venture capital executive. He founded the American Dream Institute, which operates as a digital engagement platform focused on helping the Democratic Party rebuild trust with young working Americans. Our Revolution endorsed Jones. As of March 2026, Thompson and Jones led the primary field in fundraising totals.

The Republican candidates in the primary included Sharon Brown, Mandy Ghusar, Jimih Jones, L. John MacKenzie, Raymond Riehle, and Chuck Uribe. Independent candidate Thomas Roach also competed in the primary.