Illinois 12th Congressional District
Congressional District 12
Covers all of Wayne County, Jackson County, Jefferson County, Marion County, Randolph County, Washington County, Clark County, Clinton County, Jasper County, White County, Effingham County, Clay County, Crawford County, Perry County, Williamson County and 14 more; parts of St. Clair County, Coles County, Alexander County, Wabash County and Hardin County.
Who Holds This Seat
Running in 2026
Republican · U.S. Representative
- Ballot
- On the 2026 ballot
- Last Change
- Profile updated · Sep 24
- Raised
- $1,350,277cycle to date through Jun 30
- Cash on Hand
- $789,999cycle to date through Jun 30
View on FEC.govFEC, cycle to date through Jun 30, 2026
Democrat
- Ballot
- On the 2026 ballot
- Last Change
- New finance report · Oct 8
- Raised
- $88,060cycle to date through Jun 30
- Cash on Hand
- $59,815cycle to date through Jun 30
View on FEC.govFEC, cycle to date through Jun 30, 2026
On File, Not Running
The District
Includes Carbondale, Centralia, Columbia, Effingham, Herrin, Marion, Marissa, Mascoutah, Mount Vernon, O'Fallon (part), Olive Branch, Salem and 263 more.
865 precincts · District lines: Congressional lines: U.S. Census Bureau (1:500,000 cartographic boundary, 119th Congress) · Precinct lines: Chicago Board of Election Commissioners, Boundaries - Ward Precincts (2023-2024) (data.cityofchicago.org 6piy-vbxa) for the City of Chicago; Cook County Clerk, Suburban Cook Election Precincts - Current (datacatalog.cookcountyil.gov k7sw-w3b8); DuPage County, Election_Precincts layer (gis.dupageco.org, current, retrieved 2026-09-24); U.S. Census Bureau 2020 VTDs elsewhere in Illinois; U.S. Census Bureau 2020 TIGER/Line VTDs where no official layer
Results in This District
| Contest | First | Second | Margin | Votes | Source |
|---|---|---|---|---|---|
| 2024 President887 precinctsIllinois State Board of ElectionsOfficial vote | Donald J. Trump (R)227,477 · 71.1% | Kamala D. Harris (D)86,134 · 26.9% | R+44.2 | 319,795 | Illinois State Board of ElectionsOfficial vote |
| 2022 U.S. Senate838 precinctsIllinois State Board of ElectionsOfficial vote | Kathy Salvi (R)174,379 · 68.8% | Tammy Duckworth (D)74,610 · 29.4% | R+39.4 | 253,497 | Illinois State Board of ElectionsOfficial vote |
| 2022 Governor754 precinctsIllinois State Board of ElectionsOfficial vote | Darren Bailey (R)187,540 · 73.4% | Jb Pritzker (D)61,806 · 24.2% | R+49.2 | 255,537 | Illinois State Board of ElectionsOfficial vote |
| 2020 President815 precinctsIllinois State Board of ElectionsOfficial vote | Donald J. Trump (R)256,985 · 69.7% | Joseph R. Biden (D)104,579 · 28.3% | R+41.3 | 368,887 | Illinois State Board of ElectionsOfficial vote |
| 2020 U.S. Senate815 precinctsIllinois State Board of ElectionsOfficial vote | Mark C. Curran Jr. (R)238,904 · 65.8% | Richard J. Durbin (D)114,536 · 31.5% | R+34.3 | 363,062 | Illinois State Board of ElectionsOfficial vote |
Totals add up the certified precinct results for the precincts inside today's district lines. A precinct split by the district line counts in full, or only in the district holding most of its voters where the linkage assigns it to one, and votes a county reported only countywide (some counties' absentee and early votes) are left out, so totals can differ from an official canvass.
Past Results
Representative in Congress, District 12
2024 General Election · Nov 5, 2024| Candidate | Party | Votes | Share |
|---|---|---|---|
| Mike BostRepublican | Republican | 272,754 | 74.2% |
| Brian RobertsDemocrat | Democrat | 94,875 | 25.8% |
| No Candidate | 0 | 0.0% |
Official vote — Illinois State Board of Elections (certified canvass, precinct vote totals by election authority) · Illinois State Board of Elections — Election Vote Totals by Precinct
Representative in Congress, District 12
2022 General Election · Nov 8, 2022| Candidate | Party | Votes | Share |
|---|---|---|---|
| Mike BostRepublican | Republican | 218,379 | 75.0% |
| Homer "chip" MarkelDemocrat | Democrat | 72,791 | 25.0% |
| Write-In | 82 | 0.0% | |
| Nancy Foster | 1 | 0.0% |
Official vote — Illinois State Board of Elections (certified canvass, precinct vote totals by election authority) · Illinois State Board of Elections — Election Vote Totals by Precinct
Representative in Congress, District 12
2020 General Election · Nov 3, 2020| Candidate | Party | Votes | Share |
|---|---|---|---|
| Mike BostRepublican | Republican | 194,839 | 60.4% |
| Raymond C. LenziDemocrat | Democrat | 127,577 | 39.6% |
Official vote — Illinois State Board of Elections (certified canvass, precinct vote totals by election authority) · Illinois State Board of Elections — Election Vote Totals by Precinct