Incumbent Mike Thompson leads trader consensus in the California 4th congressional district race due to his long tenure since 1998, strong primary performance, and the district’s solid Democratic rating from forecasters despite redistricting that added more rural counties. The June 2, 2026, top-two primary advanced Thompson and fellow Democrat Eric Jones to the November 3 general election, with Thompson capturing roughly 41% to Jones’s 22%. Jones, a younger progressive former venture capitalist who self-funded heavily, has drawn endorsements including from the former Republican primary contender, but faces structural barriers from Thompson’s name recognition and committee role. These factors align with current implied probabilities favoring the incumbent while leaving room for shifts from turnout patterns or late campaign developments.