Illinois Senate
2026 forecast. Updated October 22, 2026, 09:28 UTC
39 of 59 seats are up in 2026. Democrats are forecast to hold 41 seats after November (80% range 39–44) and Republicans 18 (15–20).
Initial version. This model was tested on every state legislative election from 1994 to 2024 before publication, forecasting each as if it had not happened. It beat the simple rule “the party that holds the seat keeps it”, and its chamber seat counts were off by 2.9 seats on average (target: under 3). Districts with no two-party race last time are read from their own presidential vote, a change tested in advance that cut their average error from 17 to 13 points. It missed one of its five accuracy targets: in 2024, the calmest year on record, its ranges were wider than they needed to be (92% of results fell inside its 80% ranges; target: at most 88%). Treat the ranges as cautious. The full test record and code.
Go to a district
Shaded by the chance of a Democratic win; pale dashed chips are not up in 2026.
Districts
Chance: of a Democratic win (in a district electing several members, of Democrats winning at least half its seats). Source: where the candidate list came from.
| District | Status | Candidates | Democratic chance | Source |
|---|---|---|---|---|
| 1 | Not up in 2026 (held by Democrat) | |||
| 2 | Decided: only a Democrat is running | Omar Aquino (D) | wikipedia primary results | |
| 3 | Decided: only a Democrat is running | Mattie Hunter (D) | wikipedia primary results | |
| 4 | Not up in 2026 (held by Democrat) | |||
| 5 | Decided: only a Democrat is running | Lakesia Collins (D) | wikipedia primary results | |
| 6 | Forecast | Sara Feigenholtz (D), Frank Rowder (R) | >99% | wikipedia primary results |
| 7 | Not up in 2026 (held by Democrat) | |||
| 8 | Forecast | Ram Villivalam (D), Vince Romano (R) | 97% | wikipedia primary results |
| 9 | Forecast | Patrick Hanley (D), Tom Lally (R) | >99% | aggregator (The Ballot Brief) |
| 10 | Not up in 2026 (held by Democrat) | |||
| 11 | Decided: only a Democrat is running | Mike Porfirio (D) | wikipedia primary results | |
| 12 | Decided: only a Democrat is running | Celina Villanueva (D) | aggregator (The Ballot Brief) | |
| 13 | Not up in 2026 (held by Democrat) | |||
| 14 | Forecast | Emil Jones III (D), Brian Skala (R) | 97% | aggregator (The Ballot Brief) |
| 15 | Decided: only a Democrat is running | Napoleon B. Harris III (D) | aggregator (The Ballot Brief) | |
| 16 | Not up in 2026 (held by Democrat) | |||
| 17 | Forecast | Elgie R. Sims Jr. (D), Frederick L. Walls (R) | 97% | aggregator (The Ballot Brief) |
| 18 | Forecast | Frances Ann Hurley (D), Christine McGovern (R) | 99% | aggregator (The Ballot Brief) |
| 19 | Not up in 2026 (held by Democrat) | |||
| 20 | Decided: only a Democrat is running | Graciela Guzman (D) | aggregator (The Ballot Brief) | |
| 21 | Forecast | Laura Ellman (D), Julie Berkowicz (R) | 99% | aggregator (The Ballot Brief) |
| 22 | Not up in 2026 (held by Democrat) | |||
| 23 | Forecast | Suzanne "Suzy" Glowiak Hilton (D), Linda Z. Polacek (R) | 97% | aggregator (The Ballot Brief) |
| 24 | Forecast | Benjamin "Ben" McAdams (D), Seth Lewis (R) | 40% | aggregator (The Ballot Brief) |
| 25 | Not up in 2026 (held by Democrat) | |||
| 26 | Forecast | Nabeela Syed (D), Darby Hills (R) | 55% | aggregator (The Ballot Brief) |
| 27 | Forecast | Carina Santa Maria (D), David Mathis (R) | 98% | aggregator (The Ballot Brief) |
| 28 | Not up in 2026 (held by Democrat) | |||
| 29 | Forecast | Julie A. Morrison (D), Kate McGrath (R) | 97% | aggregator (The Ballot Brief) |
| 30 | Decided: only a Democrat is running | Adriane L. Johnson (D) | aggregator (The Ballot Brief) | |
| 31 | Not up in 2026 (held by Democrat) | |||
| 32 | Forecast | Karen Battaglia (D), Craig Wilcox (R) | 14% | aggregator (The Ballot Brief) |
| 33 | Forecast | Michele Clark (D), Danielle Penman (R) | 8% | aggregator (The Ballot Brief) |
| 34 | Not up in 2026 (held by Democrat) | |||
| 35 | Forecast | Sarah B. Mertens (D), Dave Syverson (R) | 5% | aggregator (The Ballot Brief) |
| 36 | Forecast | Michael W. Halpin (D), Brad Beekman (R) | 97% | aggregator (The Ballot Brief) |
| 37 | Not up in 2026 (held by Republican) | |||
| 38 | Forecast | Ernie R. Marcelain (D), Sue Rezin (R) | 5% | aggregator (The Ballot Brief) |
| 39 | Decided: only a Democrat is running | Don Harmon (D) | aggregator (The Ballot Brief) | |
| 40 | Not up in 2026 (held by Democrat) | |||
| 41 | Decided: only a Republican is running | John Curran (R) | aggregator (The Ballot Brief) | |
| 42 | Forecast | Jared Ploger (D), Edgardo "Eddie" Perez (R) | 99% | aggregator (The Ballot Brief) |
| 43 | Not up in 2026 (held by Democrat) | |||
| 44 | Decided: only a Republican is running | Sally J. Turner (R) | aggregator (The Ballot Brief) | |
| 45 | Forecast | Joseph H. "Joe" Berning (D), Andrew S. Chesney (R) | <1% | aggregator (The Ballot Brief) |
| 46 | Not up in 2026 (held by Democrat) | |||
| 47 | Decided: only a Republican is running | Neil Anderson (R) | aggregator (The Ballot Brief) | |
| 48 | Forecast | Doris Turner (D), Frank Lesko (R) | 90% | aggregator (The Ballot Brief) |
| 49 | Not up in 2026 (held by Democrat) | |||
| 50 | Decided: only a Republican is running | Jil Tracy (R) | aggregator (The Ballot Brief) | |
| 51 | Decided: only a Republican is running | Chapin Rose (R) | aggregator (The Ballot Brief) | |
| 52 | Not up in 2026 (held by Democrat) | |||
| 53 | Decided: only a Republican is running | Chris Balkema (R) | aggregator (The Ballot Brief) | |
| 54 | Decided: only a Republican is running | Steve McClure (R) | aggregator (The Ballot Brief) | |
| 55 | Not up in 2026 (held by Republican) | |||
| 56 | Forecast | Erica Harriss (R), Marsia Geldert-Murphey (D) | 47% | wikipedia primary results |
| 57 | Forecast | Christopher Belt (D), Daniel Rhyne (R) | 99% | wikipedia primary results |
| 58 | Not up in 2026 (held by Republican) | |||
| 59 | Forecast | Paul Jacobs (R), Tamiko "T.c." Mueller (D) | 5% | wikipedia primary results |