Illinois State Senate seat · lines in effect since 2022
Illinois Legislative District 55
A district of about 207,000 people, 25% of adults with a bachelor's degree. It votes R+47.4 relative to the nation for president.
2024 election
Nov 5, 2024- Jason Plummer (R) · won100.0%
Unopposed.
Source: MIT Election Data and Science LabUpdated Sep 30, 2026, 12:13 PM ET
Where it sits among all 59 seats
Every Illinois 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
18 races since 1970. 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 | Jason Plummer (R) | — | Unopposed |
| 2022 | Jason Plummer (R) | — | Unopposed |
| Lines first used in 2012 | |||
| 2020 | Darren Bailey (R) | Cynthia Ann Given (D) | 53.4 |
| 2016 | Dale A. Righter (R) | — | Unopposed |
| 2012 | Dale A. Righter (R) | — | Unopposed |
| Lines first used in 2002 | |||
| 2010 | Dale A. Righter (R) | Josh Weger (D) | 43.7 |
| 2006 | Dale A. Righter (R) | — | Unopposed |
| 2002 | Dale A. Righter (R) | — | Unopposed |
| Lines first used in 1992 | |||
| 1998 | Frank Watson (R) | Kristi Vetri (D) | 38.6 |
| 1996 | Frank Watson (R) | David Ahola (D) | 35.7 |
| 1992 | Frank Watson (R) | Craig Virgin (D) | 10.7 |
| Lines first used in 1982 | |||
| 1988 | Frank Watson (R) | Wilma R. Pidgeon (D) | 28.1 |
| 1984 | Frank Watson (R) | David Vaught (D) | 27.4 |
| 1982 | Frank Watson (R) | Herbert B. Schlarmann (D) | 16.2 |
| Lines first used in 1972 | |||
| 1978 | James H. Donnewald (D) | Jack Brown (R) | 26.8 |
| 1974 | James H. Donnewald (D) | Herschel Kasten (R) | 21.0 |
| 1972 | James H. Donnewald (D) | Kathleen Odell (R) | 7.9 |
| Lines first used in 1962 | |||
| 1970 | Terry L. Bruce (D) | George W. Woodcock (R) | 4.9 |
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 55
The state's districts in other chambers that share residents with this one, and the share of District 55's area in each.
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+45.8 | No race | R+45.1 | R+46.6 |
| U.S. Senate | R+20.3 | No race | R+38.2 | No race |
| Governor | No race | R+29.2 | 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 59 seats. Small marks are other seats in Illinois. The black marker is District 55.
Lower than 76% of seats.
Higher than 91% of seats.
Lower than 98% of seats.
Lower than 90% of seats.
Lowest of 59 seats.
Less dense than 91% 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 5024% college gradsR+45.8Held RDistrict 51
25% college gradsR+45.1Held RDistrict 54
25% college gradsR+45.1Held RDistrict 58
21% college gradsR+49.9Not 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