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2026 Senate forecast: Polymarket odds for every race

Updated September 24, 2026 at 17:34 UTC · refreshed twice a day · Election Day is November 3, 2026

Polymarket gives the Democratic Party a 62.5% chance to win the Senate in 2026 (as of September 24, 2026). Across 35 races with a Polymarket winner market, Democrats are favoured in 17 and Republicans in 17, other candidates in 1; the closest: Iowa (Ashley Hinson 53.5%), Ohio (Sherrod Brown 59.5%); the most likely Republican Senate seat count is ≤47 (37.5%).

Who wins the Senate?

OutcomeChance
Democratic Party62.5%
Republican Party37.5%

Republican Senate seats after the midterms

OutcomeChance
≤4737.5%
4815.5%
4913.5%
5010.5%
518.5%
525.5%
533.1%
542.1%
550.6%
560.2%
57+0.5%

Balance of power: Senate and House together

OutcomeChance
Democrats Sweep63.5%
D Senate, R House1.1%
R Senate, D House30.5%
Republicans Sweep7.5%

Every Senate race by rating

Toss-up: 2 · Lean: 6 · Likely: 11 · Safe: 16. Ratings come from the favourite's price: safe 95%+, likely 80–95%, lean 60–80%, toss-up below 60%.

StateDemocratRepublicanRatingKalshi D / RVolume
IowaJosh Turek 46.5%Ashley Hinson 53.5%Toss-up44.5% / 55.5%$565.8K
OhioSherrod Brown 59.5%Jon Husted 39.5%Toss-up59.5% / 40.5%$723.0K
TexasJames Talarico 61.5%Ken Paxton 39.5%Lean Democrat58.5% / 42.5%$1.49M
MaineTroy Jackson 67.5%Susan Collins 32.5%Lean Democrat66.5% / 34%$1.85M
NebraskaDemocrat 0.4%Pete Ricketts 68.5%Lean Republican0.4% / 70.5%$375.6K
KansasAdam Hamilton 30.5%Roger Marshall 69.5%Lean Republican31% / 69.5%$185.7K
MichiganAbdul El-Sayed 71.5%Mike Rogers 28.5%Lean Democrat73.5% / 27.5%$1.04M
AlaskaMary Peltola 73.5% · Sen. Dan Sullivan 26.5% (no party labels in this market)Lean (Mary Peltola)70.5% / 28.5%$1.01M
New HampshireChris Pappas 84.5%John E. Sununu 14.5%Likely Democrat86.5% / 13.5%$239.9K
South CarolinaAnnie Andrews 13.5%Darline Graham Nordone 86.5%Likely Republican13.5% / 86.5%$332.1K
MontanaAlani Bankhead 0.4%Kurt Alme 89%Likely Republican1.0% / 90.5%$133.7K
FloridaAngie Nixon 8.5%Ashley Moody 91.5%Likely Republican11.5% / 89.5%$128.1K
MississippiScott Colom 8.5%Cindy Hyde-Smith 92%Likely Republican9.0% / 91.1%$97.9K
MinnesotaPeggy Flanagan 92.5%Michele Tafoya 7.5%Likely Democrat90.5% / 9.8%$96.1K
LouisianaJamie Davis 6.5%Julia Letlow 93%Likely Republican5.2% / 94.8%$38.1K
GeorgiaJon Ossoff 94.5%Mike Collins 5.4%Likely Democrat94.6% / 5.8%$166.0K
North CarolinaRoy Cooper 94.5%Michael Whatley 6.5%Likely Democrat93.7% / 6.5%$175.5K
IdahoDemocrat 0.9%Jim Risch 94.6%Likely Republican0.5% / 92.5%$43.2K
ArkansasHallie Shoffner 4.9%Tom Cotton 94.7%Likely Republican7.2% / 92.9%$19.1K
South DakotaDemocrat 0.1%Mike Rounds 95.2%Safe Republican0.4% / 92.1%$35.0K
KentuckyCharles Booker 3.1%Andy Barr 95.8%Safe Republican$34.4K
AlabamaEverett Wess 2.5%Barry Moore 96%Safe Republican3.6% / 97.5%$12.9K
ColoradoJohn Hickenlooper 96.2%Mark Baisley 3.0%Safe Democrat98.4% / 1.4%$49.1K
OklahomaN’Kiyla “Jasmine” Thomas 3.2%Kevin Hern 96.5%Safe Republican2.5% / 97.4%$26.2K
TennesseeMarquita Bradshaw 3.3%Bill Hagerty 96.6%Safe Republican2.9% / 97.2%$29.9K
New JerseyCory Booker 96.8%Justin Murphy 3.4%Safe Democrat97.8% / 1.3%$21.2K
WyomingJames W. Byrd 2.8%Harriet Hageman 96.9%Safe Republican1.8% / 98%$17.9K
New MexicoBen Ray Luján 97%Larry Marker 3.1%Safe Democrat97.4% / 2.5%$26.0K
VirginiaMark Warner 97.5%Bert Mizusawa 1.6%Safe Democrat97.6% / 2.7%$23.6K
OregonJeff Merkley 97.6%David Brock Smith 2.1%Safe Democrat97.8% / 2.1%$6.7K
IllinoisJuliana Stratton 97.8%Don Tracy 2.5%Safe Democrat98.6% / 2.2%$33.5K
MassachusettsEd Markey 97.9%John Deaton 1.9%Safe Democrat98.2% / 1.4%$48.4K
DelawareDemocrat 98.3%Republican 1.4%Safe Democrat98.6% / 0.8%$31.6K
West VirginiaRachel Fetty Anderson 2.1%Shelley Moore Capito 98.4%Safe Republican1.7% / 97.9%$16.0K
Rhode IslandJack Reed 99.5%Raymond McKay 0.9%Safe Democrat99% / 1.1%$26.6K

Polymarket vs Kalshi: across 33 races priced on both exchanges, the Democratic candidate's price differs by 0.9 points on average; the widest gap is Texas (Polymarket 61.5%, Kalshi 58.5%). Kalshi prices are the midpoint of its best bid and ask. Control of the chamber on both: Polymarket vs Kalshi.

Independent and third-party candidates priced at 10% or more: Nebraska (Independent 32.5%); Montana (Independent 11%).

Races led by a candidate without a party label in the market: Alaska (Mary Peltola 73.5%).

Prices are Polymarket share prices read as probabilities, not polls and not quotes you can trade at; the two sides can add up to slightly more or less than 100%. Educational information, not betting advice.

More: 2026 midterm forecast (all chambers) · Governor forecast · House forecast · 2026 elections by state · All senate markets · 2026 midterms odds · 2026 midterms guide · Odds on people

Frequently asked questions

Who is favoured to win the Senate in 2026?

Polymarket gives the Democratic Party a 62.5% chance to win the Senate in 2026 (as of September 24, 2026). Across 35 races with a Polymarket winner market, Democrats are favoured in 17 and Republicans in 17, other candidates in 1; the closest: Iowa (Ashley Hinson 53.5%), Ohio (Sherrod Brown 59.5%); the most likely Republican Senate seat count is ≤47 (37.5%).

Which senate races are toss-ups?

Races where no candidate is priced at 60% or more: Iowa (Ashley Hinson 53.5%); Ohio (Sherrod Brown 59.5%).

How are the ratings set?

From the favourite's price in each race's Polymarket winner market: 95% or more is safe, 80–95% likely, 60–80% lean and below 60% a toss-up. They are market prices, not polls or a model, and they move with every trade.

How do Polymarket's senate race odds compare with Kalshi's?

Across 33 races priced on both exchanges the Democratic candidate's price differs by 0.9 points on average; the widest gap is Texas (Polymarket 61.5%, Kalshi 58.5%).

How often are Polymarket election favourites right?

Our accuracy study checks resolved Polymarket markets against the price a week before close: polymarkettrader.com/odds/accuracy/.

Free JSON: /api/v1/midterms-2026.json (CC BY 4.0). Polymarket View is independent and not affiliated with Polymarket, any party or campaign.