Washington State Senate seat · lines in effect since 2024
Washington Legislative District 10
A district of about 171,000 people, 32% of adults with a bachelor's degree. It votes D+7.9 relative to the nation for president.
2024 election
Nov 5, 2024- Ron Muzzall (R) · won50.9%
- Janet St Clair (D)48.9%
Source: Washington Secretary of StateUpdated Sep 30, 2026, 12:29 PM ET
Where it sits among all 49 seats
Every Washington 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 2024 | |||
| 2024 | Ron Muzzall (R) | Janet St Clair (D) | 2.0 |
| Lines first used in 2012 | |||
| 2020 | Ron Muzzall (R) | Helen Price Johnson (D) | 1.9 |
| 2016 | Barbara Bailey (R) | Angie Homola (D) | 13.4 |
| 2012 | Barbara Bailey (R) | Mary Margaret Haugen (D) | 5.6 |
| Lines first used in 2002 | |||
| 2008 | Mary Margaret Haugen (D) | Linda Haddon (R) | 7.2 |
| 2004 | Mary Margaret Haugen (D) | April L. Axthelm (R) | 3.2 |
| Lines first used in 1992 | |||
| 2000 | Mary Margaret Haugen (D) | Norma Smith (R) | 4.9 |
| 1996 | Mary Margaret Haugen (D) | Jim Youngsman (R) | 5.4 |
| 1992 | Mary Margaret Haugen (D) | Caldwell (R) | 17.1 |
| Lines first used in 1982 | |||
| 1988 | Jack Metcalf (R) | Keith Wilson (D) | 11.3 |
| 1984 | Jack Metcalf (R) | Steve Talmadge (D) | 18.5 |
| Lines first used in 1972 | |||
| 1980 | Jack Metcalf (R) | Bill Daugherty (D) | 25.4 |
| 1976 | F. Wanamaker (R) | Jim Shipman (D) | 0.2 |
| 1972 | F. Wanamaker (R) | Terry Rielly (D) | 4.8 |
| Lines first used in 1962 | |||
| 1968 | Charles W. Elicker (R) | John C. Merkel (D) | 8.7 |
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 10
The state's districts in other chambers that share residents with this one, and the share of District 10'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.
| 2020 | |
|---|---|
| President | D+7.4 |
| Governor | R+0.4 |
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 49 seats. Small marks are other seats in Washington. The black marker is District 10.
Lower than 56% of seats.
Higher than 79% of seats.
Higher than 56% of seats.
Lower than 62% of seats.
Lower than 65% of seats.
Less dense than 65% 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. 1 of the 4 flipped this year.
District 3530% college gradsD+0.3Flipped DDistrict 26
37% college gradsD+8.6Held DDistrict 42
34% college gradsD+11.3Held DDistrict 17
38% college gradsD+8.4Not 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