In California's 4th congressional district, the June 2026 top-two primary advanced two Democratic candidates—incumbent Mike Thompson and challenger Eric Jones—to the November general election, with Republicans failing to secure a spot. This outcome, in a district rated solid or safe Democratic by multiple forecasters and featuring a partisan lean around D+8 after recent redistricting, has produced a near-certain Democratic hold according to trader consensus. The district's voter registration edge for Democrats and its composition, including wine country areas alongside some newly added rural territory, reinforce the positioning. A Republican victory would require an unprecedented reversal, such as a major candidate withdrawal or unforeseen disqualification before election day.