With just a week left for the US midterm elections, betting markets suggest that President Donald Trump‘s Republican Party could lose control of Congress. Democrats have strong chances to win the House of Representatives, while the race for the Senate remains tighter.According to prediction markets Kalshi and Polymarket, Democrats have a roughly 90% chance of taking control of the House of Representatives. Their chances of winning the Senate are lower, at around 65%.The November 3 elections will decide which party controls the two chambers of Congress for the remaining two years of Trump’s presidency. Republicans currently control both, giving the president an advantage in pushing through his policies.
House: Democrats ahead in betting markets
All 435 seats in the House of Representatives will be up for election on November 3. A party needs at least 218 seats to secure a majority.According to Kalshi’s October 26 figures, Democrats have a 91% chance of winning control of the House, compared with 9% for Republicans. Polymarket shows a similar trend, giving Democrats a 92% chance.The numbers have also changed over the past few months. In May, Kalshi projected that Democrats would win around 226 seats. By October 26, that figure had risen to 238, well above the majority mark.
Democrats have over a 90% chance of taking control of the House of Representatives
Senate: A closer contest
The race for the Senate is tighter, although betting markets give Democrats an advantage here also.According to Kalshi, Democrats have a 63% chance of taking control of the Senate, while Polymarket puts their chances at 66%.Unlike the House, where all seats are contested, 35 Senate seats are up for election this year, including special elections. Republicans currently hold 53 seats, while Democrats and independents who caucus with them hold 47.To win, Democrats need to gain control of Republican-held seats while retaining those they already have.Kalshi’s latest figures give Democrats a 73% chance of winning in Alaska, 68% in Ohio and 66% in Texas. In Maine, their chances stand at 59%.In June, Kalshi put Democrats’ chances of taking control at less than 43%. By late October, that figure had climbed to around 65%.
A Republican victory in both chambers is given a much lower chance, at 9.3% on Kalshi and 8% on Polymarket
Vivek Ramaswamy ‘s Ohio contest
The betting markets are also tracking the Ohio governor’s race, where Indian-American Republican Vivek Ramaswamy is contesting against Democrat’s Amy Acton.According to the latest figures, Kalshi gave Ramaswamy a 18% chance of winning, compared with 82% for Acton. Polymarket showed similar numbers, putting Ramaswamy at 18% and Acton at 83%.Ramaswamy, who previously ran for the Republican presidential nomination, is seeking to succeed Mike DeWine, who cannot contest another consecutive term.The Ohio governor’s race is separate from the battle for control of Congress, but will also be decided on November 3.
What are the possible outcomes?
Beyond individual races, prediction markets are tracking the chances of each party controlling Congress after the election.According to Kalshi, traders put the chances of Democrats winning both chambers at 64%, while Polymarket puts the figure at around 66%.The possibility of Democrats winning the House while Republicans retaining the Senate stands at 28% on Kalshi and 27% on Polymarket.A Republican victory in both chambers is given a much lower chance, at 9.3% on Kalshi and 8% on Polymarket.
What do the numbers mean for Trump
Republicans currently control both chambers of Congress, allowing Trump to pursue his legislative agenda with support from his party.If Democrats take control of the House, they could block Republican-backed legislation and launch investigations into the administration. A Democratic-controlled Senate would also affect Trump’s ability to secure confirmation for senior government and judicial appointments.However, prediction-market figures are not opinion polls. They reflect the prices at which traders buy and sell contracts on election outcomes, and can change as new information emerges. The final decision rests with the voters who will cast their ballots on November 3.
