Sep 8, 2026
Probability rose from 1.9% to 4.4% — a 2.4-point move over the past day.
Republican Trifecta & Supermajority in Midterms: Odds & Probability
Prediction markets price the chance of a Republican trifecta with a Senate supermajority in the 2026 midterms at 2.9%, making it a long shot. For this to resolve Yes, the party must control the presidency, the House, and hold at least 60 Senate seats after the November elections.
2.9%0.0 pts 24h
Updated · Volume $177.4K
The Yes contract is the only one traded; all other electoral results fall under the No side.
Context
Aug 11, 2026
Probability fell from 6.3% to 3.5% — a 2.9-point move over the past day.
Aug 10, 2026
Probability rose from 4.2% to 6.3% — a 2.2-point move over the past day.
The market now assigns a 2.9% chance to a Republican supermajority trifecta. In the past day, the odds moved by 0.0 pts. Total volume traded sits at $177.4K. To resolve to Yes, the Republicans must win a majority in the House, hold at least 60 Senate seats, and control the presidency after the November 2026 elections, including any special elections scheduled by October 31, 2026. House control is determined by a majority of voting seats; if ambiguous, the speaker’s party affiliation decides. Vacant Senate seats without a concurrent election are counted for the party of the last incumbent. The resolution relies on consensus from the Associated Press, Fox News, and NBC, or official certification if they disagree. The odds will fluctuate with electoral forecasts as the midterms approach. The fixed settlement date is Nov 3, 2026, though the market may stay open if runoffs could affect the supermajority count. Any change in polling or seat projections for either chamber could shift the probability.
FAQ
What exactly constitutes a “trifecta with a Senate supermajority”?
The Republican Party must control the presidency and the House of Representatives, and hold at least 60 seats in the Senate after the 2026 midterm elections.
How is House control determined?
A party controls the House by winning a majority of voting seats. If control is ambiguous, the market resolves based on the party affiliation of the first Speaker selected after the elections.
What happens to vacant Senate seats?
If a Senate seat is vacant but no election is held in November 2026, it is treated as held by the party of the most recent incumbent.
Which sources are used to resolve the market?
The market relies on race calls by the Associated Press, Fox News, and NBC. If they do not reach a consensus, resolution falls to the official certification.
Could runoffs delay the resolution?
Yes. If any required runoff for a November 2026 election could change the supermajority outcome, the market remains open until that runoff is conclusively called.
Data: Polymarket · Methodology · Not financial advice