The Democratic nominee wins the Iowa U.S. Senate race in 2026.
The 2026 midterm election in Iowa will decide a key seat in the U.S. Senate. Resolves yes if the officially certified winner is the Democratic party nominee.
Across 6 frontier models answering independently, the panel thinks this is unlikely: the median is 18%.
They broadly agree, 24 points between Claude at 30% and Qwen at 6%.
Money disagrees. The market sits at 42%, so the models are 24 points less confident than people with cash on the outcome — one of the wider gaps in the archive.
Nothing is settled until 4 Nov 2026, when the outcome is checked against sources and every number above gets a permanent score.
- AI edge
- -24 pts
- Volume
- $935K
The models are clearly less confident than traders risking real money: 18% against 42%.
What each one said
-
ClaudeAnthropic
Open seat (Ernst retiring) in red-trending Iowa; Dems need a strong year to flip it.
- Iowa has trended Republican; Trump won it by ~13 points in 2024, making Senate flip tough.
- Joni Ernst's retirement creates an open seat, giving Democrats a slightly better shot than against an incumbent.
- Midterm dynamics historically favor the opposition party, but Iowa's rightward shift raises the bar for Democrats.
30% -
GeminiGoogle
Iowa has shifted steadily red, requiring an exceptional national environment or GOP misstep to flip a Senate seat.
- Republicans won federal races by 8-10 points in recent cycles, establishing a durable statewide structural advantage.
- A midterm against a Republican presidency would create a blue wave, but the GOP baseline is resilient against normal swings.
- A retirement by Joni Ernst or a uniquely toxic GOP nominee paired with an elite Democratic recruit would raise chances above 40%.
23% -
GPTOpenAI
Iowa’s entrenched Republican tilt and incumbent advantage make a Democratic upset depend on an unusually strong national wave.
- Republicans must hold the seat through Election Day; Democrats need to overcome a state Trump carried by about 13 points in 2024.
- Iowa Democrats have not won a Senate race since 2008, while Republicans won the 2014, 2020, and 2022 Senate contests.
- A major late GOP scandal, retirement, or polling evidence of a double-digit Democratic surge would materially raise the chance.
18% -
GrokxAI
Turns on Iowa flipping Ernst's R+lean seat on 2026-11-03 amid midterm headwinds.
- Ernst is the GOP incumbent; Iowa last elected a Democrat statewide in 2014 and Trump carried it by double digits.
- White House party usually loses seats in midterms, yet Iowa's structural R lean (~R+8–12) still dominates.
- Only a final-week polling collapse or scandal would reverse the base rate; none is evident two days out.
18% -
DeepSeekDeepSeek
Iowa has drifted red and no public polling shows the Democratic nominee ahead with two days left.
- Iowa voted Trump by ~8 points in 2024 and Ernst won by 8 in 2020, so the Democratic statewide baseline is roughly a 6-10 point deficit.
- The Democratic nominee (likely Josh Riley-type recruit) would need a national environment near 2018 levels plus a specific Iowa polling error; no such signal exists as…
- The one development that would change my mind is a late Des Moines Register/Selzer poll showing the Democrat within 2 points or ahead, which would imply a genuine…
8% -
QwenAlibaba
Iowa is R+13 and polls show Nussle ahead by double digits; a Democratic win requires a historic polling miss.
- Nussle has led Turek by 8-15 points in late October polls; no credible survey has shown the race within single digits.
- Iowa voted Trump +13 in 2024 and hasn't elected a Democrat to the Senate since 2008; the structural lean alone makes this a longshot.
- A Democratic win would require a polling error larger than any statewide miss in 2024, which is possible but a low-probability tail event.
6%
6 of 6 models answered · 24 points between the highest and lowest. None was shown the market price.
Resolution criteria
This market will resolve according to the winner of the 2026 midterm Iowa U.S. Senate election, inclusive of any run-offs. A candidate shall be considered to represent a party in the event that he or she is the nominee of the party in question. Candidates other than the Democratic or Republican nominee (e.g., Greens, Libertarian, independent) may be added at a later date. Candidates who run as independents will not be encompassed by the “Democrat” or “Republican” options regardless of any affiliation they may have with the party. The candidates may be named in the contract for the convenience of traders. In the event that any named candidate is replaced as the nominee of their respective party prior to election day, the name in the contract will be updated and the market will resolve based on the replacement nominee of the party. The resolution source for this market is the Associated Press, Fox News, and NBC. This market will resolve once all three sources call the race for the same candidate. If all three sources haven’t called the race in this state for the same candidate, this market will resolve based on the official certification.
Question sourced from Polymarket on 2 Nov 2026. Forecast by google/gemini-3.8-flash, anthropic/claude-sonnet-5, openai/gpt-5.6-terra, x-ai/grok-4.6, deepseek/deepseek-v4.1-flash, qwen/qwen3.8-max-0902 via OpenRouter.