2026 Midterm Election Tracker

The 2026 U.S. midterm elections are held on Tuesday, November 3, 2026. All 435 seats in the House of Representatives, 33–35 Senate seats, and 36 governorships are on the ballot.

Prediction markets and Octagon's model currently favor the Democratic party to win the U.S. House, with an implied probability near 85%. Odds update as markets move.

Each race links to an Octagon research report that pairs live prediction-market prices from Kalshi and Polymarket with an AI-generated model probability, an executive summary, and the key factors that could move the race.

The market probability is the price traders are paying on Kalshi or Polymarket. The Octagon model probability is our independent estimate of the outcome, so a gap between the two flags a potential mispricing.

The most competitive 2026 Senate races on this tracker — where the favored candidate is under 65% — currently include Texas, Maine, Ohio, Iowa, Michigan. Toss-up races are listed first in the Senate and Governor sections.

This tracker shows live control-of-the-Senate odds in the Balance of Power section, combining Kalshi and Polymarket prices with Octagon's model probability. The favored party updates as the markets move.

There are 37 days until Election Day on Tuesday, November 3, 2026.