Colorado Senate
2026 forecast. Updated October 22, 2026, 09:28 UTC
21 of 35 seats are up in 2026. Democrats are forecast to hold 23 seats after November (80% range 21–24) and Republicans 12 (11–14).
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 | Forecast | Jamie Jeffery (D), Byron Pelton (R) | 5% | official |
| 2 | Not up in 2026 (held by Republican) | |||
| 3 | Forecast | Aaron Gutierrez (D), Dana Charles (R) | 77% | official |
| 4 | Forecast | Justin Kurth (D), Teddy Collins (R) | 4% | official |
| 5 | Not up in 2026 (held by Republican) | |||
| 6 | Not up in 2026 (held by Republican) | |||
| 7 | Decided: only a Republican is running | Janice Rich (R) | official | |
| 8 | Forecast | Dylan Roberts (D), Corey Marshall (R) | 98% | official |
| 9 | Forecast | Terri Carver (R), William Delano Moses III (D) | 1% | official |
| 10 | Not up in 2026 (held by Republican) | |||
| 11 | Forecast | Tony Exum Sr. (D), Levon Stilson (R), Janet Turner (Libertarian) | 93% | official |
| 12 | Not up in 2026 (held by Democrat) | |||
| 13 | Not up in 2026 (held by Republican) | |||
| 14 | Not up in 2026 (held by Democrat) | |||
| 15 | Forecast | Rob Woodward (R), Janice Marchman (D) | 85% | official |
| 16 | Not up in 2026 (held by Democrat) | |||
| 17 | Forecast | Katie Wallace (D), Pat Miller (R) | >99% | official |
| 18 | Not up in 2026 (held by Democrat) | |||
| 19 | Not up in 2026 (held by Democrat) | |||
| 20 | Forecast | Richard (Rich) Mancuso (R), Sheila Lieder (D) | 94% | official |
| 21 | Forecast | Frederick Alfred Jr. (R), Adrienne Benavidez (D) | 87% | official |
| 22 | Forecast | Steve Harkess (R), Monica Irasema Duran (D) | >99% | official |
| 23 | Not up in 2026 (held by Republican) | |||
| 24 | Forecast | Kevin Allen (R), Kyle Mullica (D) | 97% | official |
| 25 | Forecast | Paul Kohlhoff (R), William Lindstedt (D), Mark Philip Bromley (independent) | >99% | official |
| 26 | Not up in 2026 (held by Democrat) | |||
| 27 | Forecast | Danielle Lammon (R), Tom Sullivan (D), Michele Poague (Libertarian) | 97% | official |
| 28 | Not up in 2026 (held by Democrat) | |||
| 29 | Forecast | Iman M. Jodeh (D), Robert McKenna (R) | 98% | official |
| 30 | Forecast | John Carson (R), Kevin Leung (D) | 21% | official |
| 31 | Decided: only a Democrat is running | Matt Ball (D) | official | |
| 32 | Forecast | Emily Sirota (D), Sydnnia Wulff (R) | >99% | official |
| 33 | Not up in 2026 (held by Democrat) | |||
| 34 | Forecast | Chela Garcia Irlando (D), Jennifer Qualteri (R), Jacob Luria (Libertarian) | 95% | official |
| 35 | Forecast | Rod Pelton (R), Duane L Gurule (D), Richard Graf (Libertarian), Travis Star Nelson (independent) | <1% | official |