Balance of Power: 2026 Midterms: R Senate, D House

30-day trend

Analysis

This probability represents the likelihood that Republicans will control the Senate while Democrats retain control of the House following the 2026 midterm elections. The current 24% estimate reflects a significant disagreement between prediction markets, with Kalshi pricing the scenario at 46% while Polymarket values it at 16%—a 30-percentage-point gap suggesting unresolved market uncertainty. This outcome would require Republicans to gain Senate seats while Democrats successfully defend their House majority, a split outcome that historically occurs less frequently than unified government. The probability will adjust as economic conditions become clearer, campaign dynamics emerge, and seat-specific races develop detail through summer and fall. The November 2026 midterm election will provide final resolution, with early voting and exit polls potentially moving markets in late October.

• ›Current Senate composition and specific seat competitiveness in 2026 races, particularly in purple-state constituencies where split-ticket voting patterns would be necessary
• ›Economic performance through mid-2026, including inflation trajectory and consumer confidence measures that typically drive midterm results
• ›House district-level fundamentals: Democrats currently hold the chamber with a slim margin, requiring strong defensive performance in suburban and swing districts
• ›The 30-point gap between Kalshi and Polymarket suggests material disagreement on either House hold probability or Senate flipping odds that may reflect different modeling assumptions
• ›Turnout composition and demographic shifts between 2024 and 2026, particularly among youth and independent voters who influence both chamber outcomes

What moved the line

• May 62026 Midterms: R Senate, D House↓4pp39→35¢ · Polymarket

Recently closed in election 2026

• Will a reconciliation bill passed the Senate before May 20, 2026last 94% · 1d
• Will John Fetterman leave the Democratic party before Jun 1, 2026last 16% · 1d
• Will the Democratic National Committee release a comprehensive post-election report of the 2024 election before Aug 1, 2026last 67% · 1d
• Balance of Power: 2026 Midterms: D Senate, R Houselast 3% · 1d
• What will any participating candidate say during California Governor Debatenolast 55% · 1d

These markets stopped trading. Last odds and any captured outcome are shown above — full settlement detail lives at the venue.

How we compute these odds