Who's running in Illinois's 12th congressional district
2 candidates are on the ballot. Below is what each one says they stand for, what they have actually done in office or in public life, and the arguments published for and against them — each quoted from a named source rather than summarised by us.
2 candidates · ballot order · Mike Bost currently holds this seat
Medium confidenceMedium confidenceThe candidate's stated positions and basic record are documented, but coverage is thin — often little independent reporting, or criticism from only one side.What would raise it: More independent reporting, a documented voting record, or published criticism from a named opponent would raise this.
What they say they stand for
Their own words. Claims, not verified facts.
Veterans' health care and benefits, as chair of the House Veterans' Affairs Committee.
Tightening rules on mail voting; he sued Illinois over its deadline for counting ballots that arrive after election day.
Gun rights; he is endorsed by the National Rifle Association's Political Victory Fund.
Opposition to abortion; he is endorsed by National Right to Life.
Agriculture and rural policy; he holds the Illinois Farm Bureau's Friend of Agriculture award.
The Republican budget agenda, including the 2025 reconciliation bill he voted for.
What they’ve actually done
Documented record from official sources.
U.S. Representative for the 12th District since 2015; re-elected in 2024 with 74.2%.
Chair of the House Committee on Veterans' Affairs.
Illinois state representative for twenty years before Congress; Marine Corps veteran and former firefighter.
Lead plaintiff in Bost v. Illinois State Board of Elections; the Supreme Court ruled 7-2 in January 2026 that he had standing to challenge the state's mail ballot deadline.
Voted for the 2025 reconciliation bill that the Congressional Budget Office estimated would cut federal Medicaid spending by about $1 trillion over ten years.
Arguments in favor
President Trump endorsed his re-election, noting he was among the first House committee chairmen to back Trump's campaign, and he is backed by the Speaker of the House and more than 150 local Republican officials.
— President Donald Trump; Speaker Mike Johnson
Gun rights, anti-abortion, farm, police and firefighter organisations have all endorsed him.
— NRA Political Victory Fund, National Right to Life, Illinois Farm Bureau ACTIVATOR, Illinois FOP State Lodge and the Associated Fire Fighters of Illinois
Arguments against
Doctors, nurses and patients gathered outside his Murphysboro district office to protest his vote for the 2025 budget bill, arguing the Medicaid and Medicare cuts in it would strip coverage from families, close rural clinics and push people to skip care. Governor JB Pritzker had publicly urged him to vote against those provisions.
— Southern Illinois health care workers and patients, reported by KFVS12; Gov. JB Pritzker
His Democratic opponent says she entered the race because when she wrote to his office about that bill she got back a form letter explaining what was good about it, and a constituent letter to the Effingham Daily News complained about not hearing from him at a district town hall.
— Julie Fortier; a constituent letter to the Effingham Daily News
What we couldn’t verify
Several of the organisational endorsements listed on his campaign site date from the 2024 cycle; whether each has been renewed for 2026 was not established. The Trump endorsement is current.
His response to the Murphysboro protest was not established from sources read.
How the Supreme Court ruling in his case has changed Illinois practice, if at all, was not established; the ruling was on standing rather than on the merits.
Universal health care; she says medical care should not be a luxury.
Integrity, accountability and accessibility from a member of Congress, including responding to constituents personally.
Affordability and the cost of living in southern Illinois.
Access to higher education.
Gun policy that she argues reflects southern Illinois views rather than Chicago's.
What they’ve actually done
Documented record from official sources.
Served four years in the U.S. Air Force, including a deployment of about four and a half months to Qatar during Operation Desert Shield; stationed at Scott Air Force Base.
Degrees in biology and mathematics from McKendree University and a PhD in biomedical sciences from Saint Louis University.
Worked in cancer research and in teaching.
Launched her campaign in October 2025 and advanced from the March 17, 2026 Democratic primary.
Has not held elected office; resident of O'Fallon for more than three decades.
Arguments in favor
We found none published about this candidate in the sources reviewed.
Arguments against
We found none published about this candidate in the sources reviewed.
What we couldn’t verify
No published criticism of Fortier by name could be found. Searched: her name with 'criticism', with 'opponent', against National Republican Congressional Committee material, against Mike Bost's campaign, and against WSIU, Illinois Public Media, the Daily Egyptian and Effingham Daily News coverage. Because no case against her exists on the record, no case for her is presented either, rather than showing her own campaign's case unanswered.
Her endorsements and fundraising were not established from sources read.
The district has voted Republican by wide margins under the current map; how she plans to change that was not established beyond her emphasis on constituent responsiveness.
Positions and criticism are quoted from the named sources, not our assessments. This is built to help you start getting informed — confirm the official candidate list with your election authority before you vote.
Illinois held its primary on March 17, 2026. Republican incumbent Mike Bost and Democrat Julie Fortier are on the November ballot. The district covers southern Illinois, from the south-eastern St. Louis exurbs down through Carbondale, Centralia and Marion, and is the most Republican seat in the state; Bost won it with 74.2% in 2024. Roster confirmed against Ballotpedia and local reporting from WSIU and the Daily Egyptian. Criticism of Fortier by name could not be found, so her entry carries no arguments in either column.
This is one contest on a longer ballot
A Illinois ballot also carries state legislative districts, county offices, judicial seats and often local questions — and which of them you vote on is decided by your street address, not your city or ZIP code.
Your ballot is determined by your election authority, not by us. Verify your registration, precinct, and sample ballot at Illinois State Board of Elections.