Prediction Markets Price 76% Chance of Democratic Sweep in 2026 Midterms

Key points

• Polymarket and Kalshi both reached all-time highs for the probability of a Democratic sweep, with figures at 76% and 75% respectively.
• The odds of Republicans retaining control of both the House and Senate dropped to approximately 6% on both platforms.
• A Reuters/Ipsos survey published on Monday indicated Trump’s approval rating stood at 32%, with registered voters favoring Democratic candidates by 46% to 38%.
• Kalshi recorded over $106 million in trading volume for the congressional balance-of-power market, while Polymarket showed over $61 million in midterm outcome trading.
• Decision Desk HQ projects Democrats will win 241 House seats, providing a 23-seat majority, and holds a 65% probability for Senate control.
• Donald Trump Jr., who serves as a strategic adviser to Kalshi and sits on Polymarket’s advisory board, previously praised these platforms for reflecting public belief.

Background

This election follows a period of rising inflation and Federal Reserve rate hikes, which contributed to economic frustration among voters. In late September, markets assigned a 73% probability to a Fed rate hike, driven by inflation hitting a four-year high. By November 2, prediction markets had already shifted to a 74% chance of Democrats winning the Senate, driven by strong polling in battleground states and a historic drop in presidential approval. Earlier in October, Trump campaigned in South Carolina to support Republican Senate candidate Darline Graham, whose odds were downgraded by the Cook Political Report. Democrats needed a net gain of four seats to overcome a 53-47 deficit in the Senate, a path that appeared feasible as red-state races shifted toward Democrats due to economic concerns.

How outlets are covering it

The Daily Beast emphasizes the 'disaster' narrative for the Trump administration, highlighting the irony that Donald Trump Jr. is a paid adviser to Kalshi and sits on Polymarket’s board, where he previously praised the platforms for allowing people to bet on what they believe will happen. The outlet notes that the rising odds reflect dire polling and the potential for Democrats to investigate the administration. In contrast, the Bergen Record focuses on the statistical models from The Economist and Decision Desk HQ, noting that while the House is likely to flip, the Senate remains a tighter battle with toss-up races in Kansas, Iowa, and Ohio. The Republican National Committee, via spokeswoman Natalie Baldassarre, dismissed the prediction markets, stating that polls and markets may present one thing, but the American people get the final say, and Republicans remain confident in their ability to protect their majorities. The sources agree on the high probability of a Democratic House win but differ in emphasis on the certainty of a full sweep versus the competitive nature of the Senate.

Why it matters

A Democratic sweep of Congress would significantly alter the balance of power in the final two years of President Trump’s second and final term. It would enable Democrats to investigate the administration, block its legislative agenda, and potentially influence judicial appointments. The outcome also reflects the impact of economic conditions, including high inflation and interest rates, on voter sentiment. The high trading volumes on prediction markets indicate significant public engagement and confidence in the likelihood of a major shift in congressional control.

What to watch

Voting is underway on November 3, 2026, with results expected to begin emerging as polls close. However, closely divided races in states like Pennsylvania, where polls remain open until 8 p.m., may not be resolved immediately. The final control of both chambers will be determined as ballots are counted, with the Senate outcome potentially remaining uncertain due to competitive races in Kansas, Iowa, and Ohio. The results will shape the legislative agenda and investigative powers of Congress for the remainder of the term.