Massachusetts 4

Thomas Stalcup (R) vs Jake Auchincloss (D).

Called by the AP: Jake Auchincloss (D). Jake Auchincloss (D) 68.4%; Thomas Stalcup (R) 31.6%. Source: The Associated Press.

Cook: Solid D. Public polls: 0.

Atlas pre-election model — built only from data frozen on October 29, 2026; first published November 3 after polls closed, so it is a test of the method, not a prediction. Republican chance in that model: 0%.