IL-12 · House · 2026
Republicans are heavily favored to win this seat
100% probability
Candidates
Last verified 2026-09-14.
Julie Fortier
Democrat
Mike Bost
Republican
Michael Joseph Bost is an American politician serving as the U.S. representative for Illinois's 12th congressional district since 2015.
Held by a Republican, seeking re-election.
Why we think this
- This district's baseline partisan lean favors Republicans by about 21 points of margin before anything else is considered.
- The seat is currently held by a Republican, who is running for re-election -- incumbents usually run ahead of their party's baseline.
Model details -- coefficients, calibration, and the full technical decomposition.
Model house-2026-panel-v1 · computed 2026-09-16