Democrats hold a 62.5% implied probability in the Arizona State Senate control market, ahead of Republicans at 34%, reflecting trader assessment of a potential chamber flip. Republicans currently hold a 17-13 majority with all 30 seats on the November 3, 2026 ballot. Recent October polling shows Democratic candidates leading multiple statewide races by double digits, driven by weaker Republican base consolidation and stronger independent support. Forecasts such as State Navigate project Democrats gaining a 17-13 edge. Democrats have targeted several competitive districts while Republicans defend their long-held majority, last flipped in the early 1990s. The outcome hinges on turnout patterns and whether the current statewide environment translates to legislative districts.