South Dakota — Senate

Mike Rounds (R) vs — (D).

Count in progress (28% of the expected vote): Mike Rounds (R) 64.2%; Brian Bengs (I) 35.8%. Source: The Associated Press.

Cook: Solid R. Public polls: 8.

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: 100%.