2026 state legislative forecast

Illinois Senate forecast

Democrats win control of the Illinois Senate in nearly every one of 2,000 simulations, against a Democratic majority today. 39 of the 59 seats are on the 2026 ballot and 20 carry over until 2028; 1 race is within a 35 to 65 split.

Safe DUpdated October 17, 2026Seats 59On the ballot 39Illinois HouseAll chambers
Chance of control
>99%D<1%R
Democratic seats, 80% range
44 to 47
Median 46 · 30 for a majority
Favored to flip
7to D0to R
After 2024: 39 D, 19 R
Environment
D +12.7
Shift from the 2024 presidential vote

Illinois Senate map

District 1, not up in 2026District 2: Democrats >99%District 3: Democrats >99%District 4, not up in 2026District 5: Democrats >99%District 6: Democrats >99%District 7, not up in 2026District 8: Democrats >99%District 9: Democrats >99%District 10, not up in 2026District 11: Democrats >99%District 12: Democrats >99%District 13, not up in 2026District 14: Democrats >99%District 15: Democrats >99%District 16, not up in 2026District 17: Democrats >99%District 18: Democrats >99%District 19, not up in 2026District 20: Democrats >99%District 21: Democrats >99%District 22, not up in 2026District 23: Democrats >99%District 24: Democrats 97%District 25, not up in 2026District 26: Democrats >99%District 27: Democrats >99%District 28, not up in 2026District 29: Democrats >99%District 30: Democrats >99%District 31, not up in 2026District 32: Democrats 59%District 33: Democrats >99%District 34, not up in 2026District 35: Democrats 68%District 36: Democrats >99%District 37, not up in 2026District 38: Democrats 81%District 39: Democrats >99%District 40, not up in 2026District 41: Democrats <1%District 42: Democrats >99%District 43, not up in 2026District 44: Democrats <1%District 45: Democrats 1%District 46, not up in 2026District 47: Democrats <1%District 48: Democrats 98%District 49, not up in 2026District 50: Democrats <1%District 51: Democrats <1%District 52, not up in 2026District 53: Democrats <1%District 54: Democrats <1%District 55, not up in 2026District 56: Democrats 95%District 57: Democrats >99%District 58, not up in 2026District 59: Democrats <1%15263334353637384044454647484950515253545556575859
Safe DLean DToss upLean RSafe RNot up in 2026

District shapes are estimated from where each district's voters live in the precinct returns, not drawn from the official boundary files.

Pick a district

Hover the map for the odds in any district. Click one to pin it here and find it in the table below.

Every seat

Average 46 D to 13 R
Not on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballotDistrict 2: Democrats win >99%District 3: Democrats win >99%District 5: Democrats win >99%District 6: Democrats win >99%District 8: Democrats win >99%District 9: Democrats win >99%District 11: Democrats win >99%District 12: Democrats win >99%District 14: Democrats win >99%District 15: Democrats win >99%District 17: Democrats win >99%District 18: Democrats win >99%District 20: Democrats win >99%District 21: Democrats win >99%District 27: Democrats win >99%District 29: Democrats win >99%District 30: Democrats win >99%District 39: Democrats win >99%District 42: Democrats win >99%District 57: Democrats win >99%District 23: Democrats win >99%District 36: Democrats win >99%District 26: Democrats win >99%District 33: Democrats win >99%District 48: Democrats win 98%District 24: Democrats win 97%District 56: Democrats win 95%District 38: Democrats win 81%District 35: Democrats win 68%District 32: Democrats win 59%District 45: Democrats win 1%District 41: Democrats win <1%District 44: Democrats win <1%District 47: Democrats win <1%District 50: Democrats win <1%District 51: Democrats win <1%District 53: Democrats win <1%District 54: Democrats win <1%District 59: Democrats win <1%Not on the 2026 ballotNot on the 2026 ballotNot on the 2026 ballot
Safe DLean DToss upLean RSafe RNot up
Democratic seats across 2,000 simulations
30 for a majority4050

Every Senate district

DistrictLast winner2026 nominees2024 leanForecastDem winRating
32Craig Wilcox 2022Karen Battaglia vs Craig WilcoxR +6.3D +1.659%Toss up
35Dave Syverson 2022Sarah B. Mertens vs Dave SyversonR +9.8D +2.968%Lean D
38Sue Rezin 2022Ernie R. Marcelain vs Sue RezinR +6.7D +6.081%Likely D
24Seth Lewis 2022Benjamin "Ben" McAdams vs Seth LewisD +3.4D +11.597%Likely D
56Erica Conway Harriss 2022Marsia Geldert-Murphey vs Erica HarrissR +1.9D +11.895%Likely D
How this is built
Each district starts from its 2024 presidential vote, read off the precincts that voted in it, and moves with the state's 2026 House forecast and the national generic ballot. Half of what the last legislative winner ran ahead of the district carries over, 2026 primary turnout moves districts where it is posted, and district and statewide legislative polls count by recency and sample. A seat with no candidate from one party is called for the other. 2,000 simulations share a national, a state and a district shock. The map's district shapes are estimated from where each district's voters are in the precinct returns. All chambers.