Incumbent Democrat Mike Thompson and challenger Eric Jones dominate fundraising and endorsements heading into California's June 2 top-two primary for the 4th Congressional District. Thompson's long tenure and backing from Governor Gavin Newsom and the state Democratic Party contrast with Jones's tech-sector support and generational appeal as a political newcomer. Redistricting under Proposition 50 incorporated more conservative counties such as Sutter and Yuba, modestly reducing the district's Democratic lean, yet no Republican or independent candidate has consolidated support or raised comparable resources. The fragmented field of six Republicans makes a second Democratic advance the most likely outcome under the nonpartisan primary rules, with late spending or endorsements as the main variables before ballots close.