- Lead
- 36,383
- Total
- 82,664
- vs nation
- D+45.5
Washington 45th State Senate District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 38,838
- Total
- 87,129
- vs nation
- D+40.1
- Lead
- 27,931
- Total
- 75,581
- vs nation
- D+34.9
- Lead
- 19,152
- Total
- 72,239
- vs nation
- D+22.7
- Lead
- 19,175
- Total
- 68,915
- vs nation
- D+20.6
- Lead
- 10,839
- Total
- 67,661
- vs nation
- D+18.5
- Lead
- 6,576
- Total
- 60,736
- vs nation
- D+10.3
- Lead
- 6,287
- Total
- 56,823
- vs nation
- D+2.5
Key facts
- 2024 presidential margin
- D+44.0MIT Election Lab
- Population
- 157,2312024 5-year
- Population density
- 1,595 / sq mi2024 5-year · TIGER/Line
- Land area
- 98.6 sq miTIGER/Line
- Median household income
- $180,1592024 5-year
- White (non-Hispanic)
- 60.9%2024 5-year
- Black
- 1.8%2024 5-year
- Hispanic / Latino
- 7.3%2024 5-year
- Peak Democratic margin
- D+44.6 in 2020MIT Election Lab
- Peak Republican margin
- R+59.0 in 1904MIT Election Lab
- Most similar
- Legislative (Senate) District 41, WA · twin score 98.5
presidential history
Party record book
Washington 45th State Senate District · the strongest Democratic and Republican presidential performances recorded here, measured three ways.
1892–2024 · 34 presidential cycles
Highest vote share
Largest share of the presidential candidate vote cast here.
Democratic
Joe Biden2020
70.7%
61,578 votes · D+44.6 · modeled estimate
Runner-up · Kamala Harris, 2024 · 69.7%
Republican
Theodore Roosevelt1904
73.3%
1,929 votes · R+59.0 · modeled estimate
Runner-up · Herbert Hoover, 1928 · 72.4%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
61,578votes
70.7% of the vote · D+44.6 · modeled estimate
Runner-up · Kamala Harris, 2024 · 57,588 votes
Republican
Ronald Reagan1984
30,832votes
60.0% of the vote · R+21.2 · modeled estimate
Runner-up · George W. Bush, 2004 · 27,915 votes
Best relative to the U.S.
This Place’s margin against the national margin in the same election — positive when it leaned toward the party more than the country did.
Democratic
Kamala Harris2024
+45.5pts D vs U.S.
Place D+44.0 · U.S. R+1.5 · modeled estimate
Runner-up · Joe Biden, 2020 · +40.1 pts
Republican
Theodore Roosevelt1904
+39.4pts R vs U.S.
Place R+59.0 · U.S. R+19.7 · modeled estimate
Runner-up · Herbert Hoover, 1928 · +30.0 pts
Current officeholders
State legislative officeholder from OpenStates nightly current-legislator data.
Senate and governor results are in the Office selector at the top of this page.
U.S. House
Each row is a county-allocated estimate of U.S. House votes for this district — county returns apportioned onto its boundary, not precinct-counted. “Vote lead” is the estimated local lead here, not necessarily the winner of the full contest.
| Year | Vote lead | Democratic | Republican | Total |
|---|---|---|---|---|
| 2020 | D | 74.4%59,800 | 25.6%20,525 | 80,325 |
| 2018 | D | 81.0%51,209 | 19.0%11,998 | 63,207 |
Washington's 45th Senate District, anchored in the Issaquah-Sammamish suburbs east of Lake Washington, has trended competitive as tech-sector growth reshaped its demographics, making it a reliable bellwether for shifts across the Eastside.
Across the recorded series it reached a Democratic high of 44.6 points in 2020 and a Republican high of 59.0 points in 1904. Between 2020 and 2024 the district moved 0.6 points toward the Republican candidate; the 2024 margin was 44.0 points.
A population of 157,231, a 61% non-Hispanic-white share, and a median household income of $180,159 describe the district. The district's voting pattern over the last decade is most similar to that of Legislative (Senate) District 41 and Legislative (Senate) District 1.
The state-senate districts whose fingerprint — 2000–2024 trajectory, demographics, ancestry, religion — sits closest to this one, and why.
Twin score (0–100) = weighted cosine between tier-standardized fingerprints: presidential margins 2000–2024 with 12-yr trend and elasticity, ACS income, age, education, population and race, top reported ancestries, and religious adherence — chips name the closest-shared dimensions and the widest gap. Re-weight the groups in the twins explorer.
District research tools
Open the source-auditable district brief for electoral baseline, electorate, current-cycle coverage, geography, official dates, and methodology. Open campaign intelligence report → · Browse all comparisons →
Washington 45th State Senate District. Akashic. https://akashic.app/sld-upper/53045/. Accessed May 20, 2026. License: CC BY 4.0.