**Mike Thompson holds a strong lead in the CA-04 general election matchup against fellow Democrat Eric Jones, with traders assigning him roughly three-quarters probability of victory.** The June 2026 top-two primary confirmed this contest after Thompson secured first place with about 41% of the vote and Jones advanced narrowly over Republican contenders for the second spot. Thompson benefits from long incumbency since 1999, extensive establishment endorsements including from party leaders and labor groups, and a substantial fundraising edge. The district's strong Democratic lean, reinforced by recent redistricting, further supports his position in this all-Democratic November 3, 2026, race. Jones, a younger progressive former venture capitalist emphasizing affordability, has not significantly narrowed the gap in the months since the primary. No major late developments have altered the fundamentals, though the race remains subject to standard campaign dynamics through Election Day.