Illinois' 4th Congressional District, a Democratic stronghold with a D+29 partisan voter index and 65% Latino population, favors the Democratic Party at 93.2% implied probability following Patty Garcia's unopposed March 17 primary win as the retiring Rep. Jesús "Chuy" García's endorsed chief of staff, signaling strong party unity and institutional support in this Chicago-based battleground. The Republican nominee, Lupe Castillo, faces steep barriers including historical low GOP performance, limited fundraising, and weak turnout among district Republicans. While independents have entered the general election race for November 3, traders see scant path for a GOP upset absent a major Democratic scandal, national Republican midterm wave, or depressed Democratic early voting turnout.
Experimental AI-generated summary referencing Polymarket data · UpdatedIL-04 House Election Winner
IL-04 House Election Winner
$25,798 Vol.
$25,798 Vol.
Democratic Party
93%
Republican Party
5%
$25,798 Vol.
$25,798 Vol.
Democratic Party
93%
Republican Party
5%
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, 11:08 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...Illinois' 4th Congressional District, a Democratic stronghold with a D+29 partisan voter index and 65% Latino population, favors the Democratic Party at 93.2% implied probability following Patty Garcia's unopposed March 17 primary win as the retiring Rep. Jesús "Chuy" García's endorsed chief of staff, signaling strong party unity and institutional support in this Chicago-based battleground. The Republican nominee, Lupe Castillo, faces steep barriers including historical low GOP performance, limited fundraising, and weak turnout among district Republicans. While independents have entered the general election race for November 3, traders see scant path for a GOP upset absent a major Democratic scandal, national Republican midterm wave, or depressed Democratic early voting turnout.
Experimental AI-generated summary referencing Polymarket data · Updated
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