Incumbent Rep. Mike Bost (R) clinched the Republican nomination unopposed in the March 17 Illinois primary for the solidly Republican 12th Congressional District (Cook PVI R+22), setting up a general election matchup against Democrat Julie Fortier, who also advanced uncontested. Bost's dominant past performances—74% in 2024, 75% in 2022—combined with a stark fundraising advantage ($481,000 cash-on-hand versus Fortier's $20,000 as of late February) and the district's heavy GOP presidential lean (71% in 2024) underpin trader consensus implying 92% Republican odds, embodying wisdom-of-crowds pricing on minimal flip risk. While barriers loom large, scenarios like a major Bost scandal, health crisis, or national midterm wave could challenge this, though safe-seat history suggests low probability ahead of November 3.
Experimental AI-generated summary referencing Polymarket data · UpdatedIL-12 House Election Winner
IL-12 House Election Winner
Republican Party
92%
Democratic Party
9%
Republican Party
92%
Democratic Party
9%
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 Rep. Mike Bost (R) clinched the Republican nomination unopposed in the March 17 Illinois primary for the solidly Republican 12th Congressional District (Cook PVI R+22), setting up a general election matchup against Democrat Julie Fortier, who also advanced uncontested. Bost's dominant past performances—74% in 2024, 75% in 2022—combined with a stark fundraising advantage ($481,000 cash-on-hand versus Fortier's $20,000 as of late February) and the district's heavy GOP presidential lean (71% in 2024) underpin trader consensus implying 92% Republican odds, embodying wisdom-of-crowds pricing on minimal flip risk. While barriers loom large, scenarios like a major Bost scandal, health crisis, or national midterm wave could challenge this, though safe-seat history suggests low probability ahead of November 3.
Experimental AI-generated summary referencing Polymarket data · Updated
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