Key Takeaways
- Prediction markets Polymarket and Kalshi give Democrats a 74% chance of winning both the House and Senate in Tuesday’s midterm elections.
- Traditional pollsters align with the betting odds, suggesting a potential “blue wave” in the midterms.
- The growing influence of these platforms has sparked concerns about their impact on voter behavior.
Polymarket and Kalshi Predict Democrat Sweep in Upcoming Elections
Prediction markets, which have proven to be somewhat reliable when it comes to political outcomes, are signaling a clear advantage for the Democratic Party on the eve of the upcoming midterm elections, when all 435 seats in the U.S. House of Representatives and 35 of the 100 seats in the U.S. Senate will be contested.
Polymarket’s Balance of Power: 2026 Midterms event market, which has a volume of over $58 million, gives Democrats a 78% chance of winning control of both the House and the Senate, while only maintaining an 18% probability for Republicans to maintain a majority in the Senate.
Similarly, Kalshi, which has a dedicated portal for the midterm elections, gives Democrats 74% odds of sweeping the election in a similar event market. The contract, which has moved over $100 million in volume, only gives Republicans a 22% chance of retaining Senate control, as of this writing.
Democrats are favored by bets in relevant individual Senate races in both platforms. For example, in Texas, James Talarico has the upper hand on both platforms 74% to 76% odds of winning the seat over Republican Ken Paxton. Troy Jackson also enjoys a lead of 73% against Maine Republican Susan Collins on both platforms, while in Michigan, Abdul El-Sayed is favored by 78% on both Polymarket and Kalshi at the moment of writing.
This time, traditional pollsters are on the side of prediction markets, with CNN’s data analyst Harry Enten describing the potential outcome as a “polling earthquake.”
“Just within the last few hours, we had the equivalent of a polling earthquake, And to keep up with the weather metaphors… it tends to point to a blue wave,” said Enten on Sunday.
Prediction markets entered the political sphere with strength after accurately predicting President Trump’s victory in 2024 when some traditional pollsters gave an edge to Democrat candidate Kamala Harris. The midterm election is the biggest relevant test for these platforms since then, with Kalshi CEO Tarek Mansour calling these “the first prediction-market election,” with over $1.4 billion traded in midterm-linked bets.
Nonetheless, since 2024, the accuracy of these platforms has been spotty at best, with prediction markets failing to track the upset victory of President Luiz Inácio Lula da Silva after giving Senator Flavio Bolsonaro the lead before the runoff election.
The influence of prediction markets on voting events is under scrutiny for the first time, with institutions like the Center for Democracy and Technology stressing that they can distort candidate decisions, impact voter behavior, and undermine confidence in election processes and outcomes.
