Colorado State Senate seat · lines in effect since 2022
Colorado Senate District 12
A district of about 151,000 people, 43% of adults with a bachelor's degree. It votes D+4.1 relative to the nation for president.
2024 election
Nov 5, 2024- Marc Snyder (D) · won48.9%
- Stan Vanderwerf (R)47.5%
- John Michael Angle (LIB)3.6%
Source: MIT Election Data and Science LabUpdated Sep 30, 2026, 12:13 PM ET
Where it sits among all 35 seats
Every Colorado State Senate seat by partisan lean, from most Democratic to most Republican. Lean is the seat's presidential vote on current lines, relative to the nation.
Democratic
Source: 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET
Every election for this seat
16 races since 1968. District numbers are redrawn after each census: each group is one set of lines.
| Year | Winner | Runner-up | Won by |
|---|---|---|---|
| Lines first used in 2022 | |||
| 2024 | Marc Snyder (D) | Stan Vanderwerf (R) | 1.5 |
| Lines first used in 2012 | |||
| 2020 | Bob Gardner (R) | Electra Johnson (D) | 20.6 |
| 2016 | Bob Gardner (R) | Manuel Quintel (I) | 50.6 |
| 2012 | Bill Cadman (R) | Dave Respecki (I) | 51.1 |
| Lines first used in 2002 | |||
| 2008 | Keith C. King (R) | Pete Lee (D) | 11.7 |
| 2004 | Andy McElhany (R) | Robert G. Herzfeld (I) | 55.6 |
| Lines first used in 1992 | |||
| 2000 | Andy McElhany (R) | Patrick L. Lilly (I) | 52.9 |
| 1996 | Mary Ann Tebedo (R) | Tony Marino (D) | 11.4 |
| 1992 | Mary Ann Tebedo (R) | — | Unopposed |
| Lines first used in 1982 | |||
| 1988 | Mary Ann Tebedo (R) | Paul Shepard Jr. (D) | 31.1 |
| 1984 | Steven J. Durham (R) | — | Unopposed |
| 1982 special | Harold L. McCormick (R) | — | Unopposed |
| Lines first used in 1972 | |||
| 1980 | Steven J. Durham (R) | Jerry Benson (D) | 48.3 |
| 1976 | Harold L. McCormick (R) | Gilchrist (D) | 35.9 |
| 1972 | Harold L. McCormick (R) | Leland M. Leeper (I) | 44.4 |
| Lines first used in 1962 | |||
| 1968 | Norman W. Ohlson (R) | Frank Onufrock (D) | 21.5 |
Won by: the winner's lead over the runner-up, in points of the vote. Source: 99chambers results archive (MEDSL, Klarner, state election offices)
Districts that overlap District 12
The state's districts in other chambers that share residents with this one, and the share of District 12's area in each.
- U.S. House
- CO-5 100%
Every race on these lines
Results recomputed from precinct returns as if today's boundaries had always existed, so years compare like for like.
| 2016 | 2018 | 2020 | 2024 | |
|---|---|---|---|---|
| President | R+7.0 | No race | No race | D+4.0 |
| U.S. Senate | R+5.2 | No race | R+0.3 | No race |
| Governor | No race | D+2.4 | No race | No race |
Outlined: the race for this seat itselfBlank: no race that year
Source: 99chambers results archive: precinct results allocated to current lines; 2026: civicAPIUpdated Nov 8, 2026, 7:01 PM ET
Who lives here, compared
Grey bars show the spread of all 35 seats. Small marks are other seats in Colorado. The black marker is District 12.
Lower than 62% of seats.
Higher than 71% of seats.
Lower than 62% of seats.
Higher than 76% of seats.
Lower than 59% of seats.
Less dense than 71% of seats.
Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current linesUpdated Oct 13, 2026, 5:06 AM ET
Seats most like this one
Nearest seats on demographics, density and lean.
District 1040% college gradsR+10.3Not up in 2026District 23
46% college gradsR+13.8Not up in 2026District 15
51% college gradsD+7.7Held DDistrict 19
51% college gradsD+19.2Not up in 2026
Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current lines; 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET