2026 results · Illinois · Illinois 12th District
Mike Bost, the Republican, wins re-election in Illinois's 12th District
Donald Trump carried the district by 43.0 points in 2024; this year's count is a 3.7-point move toward the Democrats.
| Candidate | Votes | Share | Share of the vote |
|---|---|---|---|
| Mike BostRepublican, incumbent | 194,651 | 69.7% | |
| Julie FortierDemocrat | 84,768 | 30.3% |
Called by Call the Map, Nov 4, 10:46 AM EST · 95% counted.
About 95% of the expected vote counted279,419 votesCount last changed Nov 7, 1:02 PM EST · checked Nov 7, 5:00 PM ESTSource: the official state and county counts, gathered by civicAPI33 of 34 counties’ own counts read so far; not yet: Alexander
The map
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About the seat
Illinois's 12th District takes in all or part of 33 counties. The Republicans held it before this election. Its voters went R+43.0 for president in 2024. Its move from that vote, 3.7 points toward the Democrats, ranks 17 of 17 among the state's districts, counting from the largest move toward the Democrats.
- 2024 president
- R+43.0
- 2024 House race, same lines
- R+48.4
- Move from 2024, rank in state
- 17 of 17
- St. Clair County14%
- Williamson County9%
- Jackson County6%
- Monroe County6%
- Effingham County5%
- Clinton County5%
- Marion County5%
- Franklin County5%
- 25 more46%
Shares are of the votes counted this year. The 2024 House figure is the same district, on the same lines.
What the count shows
Added together, the 33 counties compared moved 3.9 points toward the Democrats from the 2024 presidential vote.
The counties compared cast 75% as many votes as in 2024, from 88% in Pulaski County to 67% in Union County.
Gallatin County moved most: R+53.5 for president in 2024, R+41.3 this year
The 10 counties with the largest moves from the 2024 presidential vote, among those with 2,000 or more votes for president in 2024 and a quarter of that counted, and at least half a percent of the state's 2024 vote. Each line runs from the 2024 margin to this year’s.
2024 president 2026
Williamson County added 5,452 net votes for Fortier against the 2024 margin, 11% of the district's change
Across the 33 counties compared, the margin moved by 50,768 votes toward Fortier: this year’s lead in votes against the 2024 presidential lead in votes, county by county. The figure counts voters who changed sides and differences in who turned out alike; the count cannot tell them apart.
- Williamson County+5,452 Fortier
- St. Clair County+5,094 Fortier
- Franklin County+3,301 Fortier
- Monroe County+3,028 Fortier
- Jefferson County+2,325 Fortier
- Randolph County+2,281 Fortier
- Clinton County+2,084 Fortier
- Effingham County+1,993 Fortier
Illinois’s ballot
StatewideDemocrats won all 6 of Illinois's statewide races.
U.S. HouseBefore the election D 14–3, now D 14–3
won leads, still counting changed party. Margins are the leader’s share minus the runner-up’s, in points.
Every count on this page is the official count, from the state and its counties. Counts are unofficial until the state certifies them. The 2024 comparison is the presidential vote, Kamala Harris against Donald Trump, on the same ground. Margins are the Democrat minus the Republican, in points of all votes.