Iowa's 3rd congressional district remains one of the most competitive House races in the 2026 midterms, with Democrat Sarah Trone Garriott challenging Republican incumbent Zach Nunn. Recent polling averages show the race within single digits, though some Democratic surveys place Trone Garriott ahead after candidate profiles, reflecting strong fundraising and early ad buys by both sides. Cook Political Report rates the seat a toss-up following its January shift from lean Republican, consistent with the district's narrow 2024 results and R+2 partisan lean. Traders appear to price in national midterm dynamics that typically favor the opposition party, alongside Trone Garriott's profile as a state senator and endorsements from reproductive rights groups. Both candidates secured uncontested primaries in June, setting up a fall contest focused on turnout in the Des Moines area and surrounding counties.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedIA-03 House Election Winner
Democratic Party
78%
Republican Party
22%
Democratic Party
78%
Republican Party
22%
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: Dec 16, 2025, 11:59 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...Iowa's 3rd congressional district remains one of the most competitive House races in the 2026 midterms, with Democrat Sarah Trone Garriott challenging Republican incumbent Zach Nunn. Recent polling averages show the race within single digits, though some Democratic surveys place Trone Garriott ahead after candidate profiles, reflecting strong fundraising and early ad buys by both sides. Cook Political Report rates the seat a toss-up following its January shift from lean Republican, consistent with the district's narrow 2024 results and R+2 partisan lean. Traders appear to price in national midterm dynamics that typically favor the opposition party, alongside Trone Garriott's profile as a state senator and endorsements from reproductive rights groups. Both candidates secured uncontested primaries in June, setting up a fall contest focused on turnout in the Des Moines area and surrounding counties.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated


Beware of external links.
Beware of external links.
Frequently Asked Questions