Incumbent Mike Thompson, a longtime moderate Democrat representing the strongly Democratic northern California district encompassing Napa and Sonoma wine country along with Sacramento suburbs, faces a top-two primary on June 2 under California's jungle primary system. Well-funded challenger Eric Jones, who has spent millions and drawn endorsements such as from Bernie Sanders, has emerged as the primary intra-party threat, while six Republicans and one independent candidate compete with far less financial support. Thompson's decades of incumbency and the district's partisan lean have shaped trader views on likely advancers, with the filing deadline passed in March and the vote just days away offering little time for late shifts in momentum.