Massachusetts 4th — House 2026 Dem Primary
The Massachusetts 4th — House dem primary is scheduled for September 1, 2026. The model makes Jake Auchincloss the heavy favorite at 97%, with Jason Poulos at 3%. Jake Auchincloss is the incumbent, leads the field in reported fundraising, and has the most tracked endorsements. No public polling is available for this race, so the forecast leans on fundraising, endorsements, candidate profiles, and historical results.
Current win probabilities
- Jake Auchincloss (incumbent) — 97%
- Jason Poulos — 3%
Probabilities update daily from polls, fundraising, endorsements, and historical results.