Incumbent Democrat Mike Thompson and challenger Eric Jones, both Democrats, advanced from the June 2026 top-two primary in California's 4th District after Republican candidates split their vote share, with the top GOP contender finishing third. Redistricting under Proposition 50 preserved the district's strong Democratic lean across Northern California counties, including wine country and Sacramento suburbs, despite incorporating some more rural areas. Forecasters rate the seat Solid or Safe Democratic, aligning with trader consensus that a Democratic winner is nearly assured ahead of the November 3 general election. A Republican victory would require an unprecedented reversal of the district's partisan composition or voter turnout patterns.