Top-two primary
All candidates run in one primary regardless of party and the two with the most votes advance, so two candidates of the same party can meet in November. The forecast then marks the seat as safe for that party.
Washington › Washington State Senate · November 3, 2026 · Updated Oct 16, 2026
Washington Legislative District 21
Top twoLiias is very likely to win: Liias wins in more than 99 of every 100 simulations.
Liias (D)
>99%
chance of winning
Khan (R)
<1%
- Average margin
- D+42.1
- 80% of outcomes
- D+33 to D+52
- Partisan lean
- D+38
- Polls
- No pollsmodel only
Liias is very likely to win: Liias wins in more than 99 of every 100 simulations.
Liias (D)
>99%
chance of winning
Khan (R)
<1%
- Average margin
- D+41.7
- 80% of outcomes
- D+29 to D+55
- Partisan lean
- D+38
- Polls
- No pollsmodel only
How this race is decided
Staggered Senate
Senators serve four-year terms; about half the seats are on the ballot each election.
Range of outcomes
Final margin across our simulations; the white dashes mark the middle 80%.
The candidates
DemocraticIncumbent
Marko Liias
- Experience
- State legislature
Republican
Riaz Khan
What goes into the forecast
Every ingredient's estimate of the final margin.
- National environment
- D+9.5Election Day forecast
- Washington state offices
- +0.0Polls for governor, statewide and legislative races · details
- Environment here
- D+9.5Used by the fundamentals
- Swing reaching this office
- 58%Of a shift in the environment, from past legislative races since 2016
- Pacific adjustment
- −1.7How legislative races in the region have run against lean and environment lately
Each estimate is a margin before national and statewide uncertainty is simulated. Horizon blends polls, fundamentals and a little of the similar-places estimate, weighting each by how precise it is; Pulse uses polls and similar places only.
Fundamentals inputs
| Incumbency (+1 D, −1 R) | 1 |
| Fundraising edge (log ratio of individual money) | 3.38 |
| Elected-experience edge | 0.67 |
| First-term incumbent | 0 |
| Seat's last result vs. expectation | 0 |
| Incumbent's last result vs. expectation | 0 |
Polls
No public polls of this race. The forecast relies on fundamentals and on polling of similar places in the state.
The district
Lean D+38: how much more Democratic or Republican than the nation it votes for president.
Presidential vote
Precinct results re-aggregated to the current district lines.
Who lives here
- Population
- 148,693
- People per km²
- 1,002
- Adults with a B.A.+
- 44%
- White, no degree
- 34%of adults
- White 56%
- Hispanic 12%
- Black 5%
- Asian 17%
- Other / multiracial 10%
American Community Survey 2020–2024, aggregated from census tracts.
Past results
Results in the same-numbered district; earlier elections may have used different lines.
2024 President Vote in this district
71,994 two-party votes · D+37.9 · D+39.4 vs. the nation✓ Kamala Harris (D)69.0%
Donald Trump (R)31.0%
2022 Earlier district lines
57,492 votes · D+26.6✓ Marko Liias (D)63.2%
Janelle Cass (R)36.6%
2020 President Vote in this district
79,044 two-party votes · D+39.0 · D+34.4 vs. the nation✓ Joe Biden (D)69.5%
Donald Trump (R)30.5%
2018 Earlier district lines
59,481 votes · D+26.3✓ Marko Liias (D)63.2%
Mario Lionel Lotmore (R)36.8%
2016 President Vote in this district
60,021 two-party votes · D+35.7 · D+33.5 vs. the nation✓ Hillary Clinton (D)67.9%
Donald Trump (R)32.1%
2014 Earlier district lines
37,098 votes · D+9.0✓ Marko Liias (D)54.5%
Dan Matthews (R)45.5%