Colorado's 4th Congressional District House race favors Republicans at 63.5% trader consensus, driven by its strong R+13 partisan lean and consistent polling leads for GOP nominee Greg Lopez, who won the June primary and a prior special election. Democratic nominee Trisha Calvarese trails in recent surveys, including an August RMG Research poll showing Lopez ahead 52%-40%, reflecting the district's rural, conservative base in eastern Colorado. Ken Buck's retirement and endorsement of Lopez bolster GOP positioning amid a favorable national House environment. No major shifts in late fundraising or endorsements have altered this dynamic, with traders pricing in low upset risk ahead of November voting.
Experimental AI-generated summary referencing Polymarket data · UpdatedCO-04 House Election Winner
CO-04 House Election Winner
Republican Party
63%
Democratic Party
37%
Republican Party
63%
Democratic Party
37%
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, 10:30 AM ET
Resolver
0x2F5e3684c...Resolver
0x2F5e3684c...Colorado's 4th Congressional District House race favors Republicans at 63.5% trader consensus, driven by its strong R+13 partisan lean and consistent polling leads for GOP nominee Greg Lopez, who won the June primary and a prior special election. Democratic nominee Trisha Calvarese trails in recent surveys, including an August RMG Research poll showing Lopez ahead 52%-40%, reflecting the district's rural, conservative base in eastern Colorado. Ken Buck's retirement and endorsement of Lopez bolster GOP positioning amid a favorable national House environment. No major shifts in late fundraising or endorsements have altered this dynamic, with traders pricing in low upset risk ahead of November voting.
Experimental AI-generated summary referencing Polymarket data · Updated
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