Missouri State Senate seat · lines in effect since 2022
Missouri Senate District 3
A district of about 181,000 people, 17% of adults with a bachelor's degree. It votes R+52.8 relative to the nation for president.
2024 election
Nov 5, 2024- Mike Henderson (R) · won75.9%
- Doug Halbert (D)24.1%
Source: MIT Election Data and Science LabUpdated Sep 30, 2026, 12:13 PM ET
Where it sits among all 34 seats
Every Missouri 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
15 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 | Mike Henderson (R) | Doug Halbert (D) | 51.7 |
| Lines first used in 2012 | |||
| 2020 | Elaine Freeman Gannon (R) | — | Unopposed |
| 2016 | Gary Romine (R) | Edward R. Weissler (I) | 62.5 |
| 2012 | Gary Romine (R) | Joseph Fallert Jr. (D) | 7.7 |
| Lines first used in 2002 | |||
| 2008 | Kevin Engler (R) | Dennis Riche (D) | 17.4 |
| 2004 | Kevin Engler (R) | Dan Ward (D) | 2.1 |
| Lines first used in 1992 | |||
| 2000 | John E. Scott (D) | Leonard F. Arons (R) | 33.8 |
| 1996 | John E. Scott (D) | Leonard F. Arons (R) | 33.6 |
| 1992 | John E. Scott (D) | Stephen O. Schaper (I) | 72.4 |
| Lines first used in 1982 | |||
| 1988 | John E. Scott (D) | Joan F. Lang (R) | 31.3 |
| 1984 | John E. Scott (D) | — | Unopposed |
| Lines first used in 1972 | |||
| 1980 | John E. Scott (D) | Orville Berg (R) | 42.9 |
| 1976 | John E. Scott (D) | — | Unopposed |
| 1972 | Lawrence J. Lee (D) | — | Unopposed |
| Lines first used in 1962 | |||
| 1968 | Lawrence J. Lee (D) | Eleanor S. Waite (R) | 35.3 |
Primaries: 1980 Democratic primary · 1972 Democratic primary · 1968 Democratic primary
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 3
The state's districts in other chambers that share residents with this one, and the share of District 3'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.
| 2018 | |
|---|---|
| U.S. Senate | R+23.4 |
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 34 seats. Small marks are other seats in Missouri. The black marker is District 3.
Lower than 97% of seats.
Highest of 34 seats.
Lowest of 34 seats.
Lower than 79% of seats.
Lower than 97% of seats.
Less dense than 76% 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 2623% college gradsR+48.4Held RDistrict 18
21% college gradsR+53.8Held RDistrict 12
21% college gradsR+56.9Held RDistrict 25
MissouriR+64.6Not 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