Washington State Senate seat · lines in effect since 2024
Washington Legislative District 18
A district of about 156,000 people, 33% of adults with a bachelor's degree. It votes D+1.7 relative to the nation for president.
2024 election
Nov 5, 2024- Adrian Cortes (D) · won50.0%
- Brad Benton (R)49.8%
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; the seat changed party 1 time. 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 | Adrian Cortes (D) | Brad Benton (R) | 0.2 |
| Lines first used in 2012 | |||
| 2020 | Ann Rivers (R) | Rick Bell (D) | 15.8 |
| 2016 | Ann Rivers (R) | Eric K. Holt (D) | 27.6 |
| 2012 | Ann Rivers (R) | Ralph Schmidt (D) | 35.7 |
| Lines first used in 2002 | |||
| 2008 | Joseph Zarelli (R) | Jon Haugen (D) | 10.1 |
| 2004 | Joseph Zarelli (R) | David L. Seabrook (D) | 7.7 |
| Lines first used in 1992 | |||
| 2000 | Joseph Zarelli (R) | Kent Landerholm (D) | 17.1 |
| 1996 | Joseph Zarelli (R) | Ted Thomas (D) | 7.6 |
| 1992 | Linda Smith (R) | Grohs (D) | 16.0 |
| Lines first used in 1982 | |||
| 1988 | Linda Smith (R)Flip | Siipola (D) | 21.8 |
| 1984 | Alan Thompson (D) | Bumala (R) | 21.5 |
| Lines first used in 1972 | |||
| 1980 | Don Talley (D) | Robert L. Engleman (R) | 29.0 |
| 1976 | Don Talley (D) | — | Unopposed |
| 1972 | Don Talley (D) | John C. Freed (R) | 47.6 |
| Lines first used in 1962 | |||
| 1968 | Don Talley (D) | Robert B. Arkell (R) | 8.2 |
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 18
The state's districts in other chambers that share residents with this one, and the share of District 18'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 | 2024 | |
|---|---|---|
| President | D+1.5 | D+2.9 |
| U.S. Senate | No race | D+3.8 |
| Governor | R+1.7 | R+1.2 |
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 18.
Lower than 52% of seats.
Higher than 77% of seats.
Higher than 50% of seats.
Lower than 60% of seats.
Lower than 62% of seats.
Denser than 62% 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 2637% college gradsD+8.6Held DDistrict 25
28% college gradsD+1.5Not up in 2026District 10
32% college gradsD+7.9Not up in 2026District 31
30% college gradsR+7.2Held R
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