Incumbent Republican Mike Bost's unopposed victory in the March 17, 2026, primary has solidified trader consensus at 93.5% for a GOP hold in the IL-12 House race, reflecting the district's strong Republican lean across southern Illinois' rural counties and Bost's track record of double-digit margins in prior cycles. Democrat Julie Fortier also advanced unopposed, but lacks the name recognition or fundraising to mount a credible challenge in this safely rated seat per nonpartisan forecasters. With no polling shifts or notable developments in the past month amid a nationally competitive generic ballot, the market anticipates continuity. Realistic disruptions would require a major scandal, health issue for Bost, or extraordinary Democratic turnout surge before the November general election.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedIL-12 House Election Winner
IL-12 House Election Winner
$18,406 Vol.
$18,406 Vol.
Republican Party
94%
Democratic Party
7%
$18,406 Vol.
$18,406 Vol.
Republican Party
94%
Democratic Party
7%
A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time all of the 2026 House elections are conclusively called by this market's resolution sources. A candidate without a ballot-listed affiliation to either the Democrat or Republican parties will be considered a member of one of these parties based on the party with which they most recently expressed their intent to caucus at the time all of the House elections are conclusively called by this market's resolution sources.
This market will resolve based on the result of the election as indicated by a consensus of credible reporting. If there is ambiguity, this market will resolve based solely on the official results as reported by the United States government, specifically the Federal Election Commission (https://www.fec.gov/).
Market Opened: Jan 28, 2026, 11:09 AM ET
Resolver
0x2F5e3684c...A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time all of the 2026 House elections are conclusively called by this market's resolution sources. A candidate without a ballot-listed affiliation to either the Democrat or Republican parties will be considered a member of one of these parties based on the party with which they most recently expressed their intent to caucus at the time all of the House elections are conclusively called by this market's resolution sources.
This market will resolve based on the result of the election as indicated by a consensus of credible reporting. If there is ambiguity, this market will resolve based solely on the official results as reported by the United States government, specifically the Federal Election Commission (https://www.fec.gov/).
Resolver
0x2F5e3684c...Incumbent Republican Mike Bost's unopposed victory in the March 17, 2026, primary has solidified trader consensus at 93.5% for a GOP hold in the IL-12 House race, reflecting the district's strong Republican lean across southern Illinois' rural counties and Bost's track record of double-digit margins in prior cycles. Democrat Julie Fortier also advanced unopposed, but lacks the name recognition or fundraising to mount a credible challenge in this safely rated seat per nonpartisan forecasters. With no polling shifts or notable developments in the past month amid a nationally competitive generic ballot, the market anticipates continuity. Realistic disruptions would require a major scandal, health issue for Bost, or extraordinary Democratic turnout surge before the November general election.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated
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