Which party will win the Senate in 2026? is a active prediction market event on Polymarket with 9 markets, $1.4M total volume, and $400.0K in liquidity. Key markets: Will the Democratic Party control the Senate after the 2026 Midterm elections?; Will the Republican Party control the Senate after the 2026 Midterm elections?; Will Party A control the Senate after the 2026 Midterm elections?.