Democrats hold an 81% implied probability of winning the Wisconsin State Senate in the November 3, 2026, election, while Republicans sit at 16%, reflecting trader consensus on chamber control. Republicans currently hold an 18-15 majority, but 17 odd-numbered seats are on the ballot, and Democrats need a net gain of just two to flip the chamber. Key drivers include new maps from the Clarke litigation, which make this cycle’s districts more Democratic-leaning than the even-numbered seats Republicans defended in 2024, plus six Republican retirements—including Majority Leader Devin LeMahieu—in competitive territory. Forecasters rate several open or targeted seats, such as the 5th, 17th, and 21st districts, as Lean Democratic or Tossup, with recent analyses projecting a Democratic edge based on 2024 presidential voting patterns and campaign focus in those races. Absentee voting is underway with three weeks until Election Day.