By Fatma Younis
Prediction markets indicate Democrats' chances of winning control of both the Senate and the House of Representatives rose sharply on Tuesday as Americans voted in the midterm elections, dealing a potential blow to President Donald Trump in his final two years in office.
Senate and House odds surge
Kalshi, a prediction market platform, gave Democrats an 80 percent chance of taking the Senate and a 95 percent chance of winning the House on election afternoon. The odds of a Democratic sweep of both chambers stood at 28 percent in January.
Polymarket, another online prediction platform, showed similar trends, with bettors assigning a 75 percent probability to a Democratic Senate takeover and a 95 percent chance for the House. The Republican Party's chance of holding the House stood at just 6 percent.
GOP sweep unlikely
Kalshi bettors put the probability of a Republican sweep of both chambers at 3.9 percent. The figures represent the Democratic Party's highest and the GOP's lowest chances of holding the House since July 2025.
Election context
While President Trump is not on the ballot, he encouraged supporters to "pretend" he is. Numerous polls have predicted difficult outcomes for Republican candidates amid public anger over the soaring cost of living and the president's unpopular war in Iran.
Senate landscape
Republicans currently hold a slim 53-47 majority in the Senate, with two independents who typically vote with Democrats. Thirty-five Senate seats are contested in the midterms.
House majority at stake
In the House, the GOP holds 219 seats to Democrats' 214, with 218 needed for a majority. Multiple polls show Democrats have a strong chance of flipping the chamber.
Key race in Texas
Democratic Senate candidate James Talarico is running neck-and-neck with Republican Attorney General Ken Paxton in Texas, a traditionally deep-red state where Democratic candidates have surged in polls.
A POLITICO poll conducted by PF Global found that around 9 percent of Trump's 2024 voters plan to cast their ballot for a Democrat in the midterms.
