Hawaii 21st State Senate District · the strongest Democratic and Republican presidential performances recorded here, measured three ways.
1960–2024 · 17 presidential cycles
Highest vote share
Largest share of the presidential candidate vote cast here.
Democratic
Lyndon B. Johnson1964
70.7%
5,149 votes · D+41.4 · modeled estimate
Runner-up · Barack Obama, 2008 · 60.9%
Republican
Richard Nixon1972
72.2%
8,427 votes · R+44.3 · modeled estimate
Runner-up · Ronald Reagan, 1984 · 65.7%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
11,061votes
52.1% of the vote · D+6.2 · modeled estimate
Runner-up · Kamala Harris, 2024 · 9,233 votes
Republican
Donald Trump2024
10,054votes
51.2% of the vote · R+4.2 · modeled estimate
Runner-up · Donald Trump, 2020 · 9,748 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
Lyndon B. Johnson1964
+18.9pts D vs U.S.
Place D+41.4 · U.S. D+22.6 · modeled estimate
Runner-up · Barack Obama, 2012 · +17.1 pts
Republican
Richard Nixon1972
+21.2pts R vs U.S.
Place R+44.3 · U.S. R+23.2 · modeled estimate
Runner-up · Gerald Ford, 1976 · +20.4 pts
current representation
Current officeholders
DMike GabbardState Senate · 21
State legislative officeholder from OpenStates nightly current-legislator data.
U.S. House elections · 3 House
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.
Source · Akashic county-allocated estimate from certified county returns, House; not precinct-counted.
Year
Vote lead
Democratic
Republican
Total
2024
D
69.9%12,994
30.1%5,605
18,599
2020
D
68.9%14,080
31.1%6,356
20,436
2018
D
76.0%8,001
24.0%2,525
10,526
Anchored in urban Honolulu, this district delivers presidential margins exceeding 40 points, reflecting a dense, heavily Democratic electorate that has shown little competitive variation in recent cycles.
Across the recorded series it reached a Democratic high of 41.4 points in 1964 and a Republican high of 44.3 points in 1972. Between 2020 and 2024 the district moved 10.4 points toward the Republican candidate; the 2024 margin was 4.2 points.
A population of 59,486, a 12% non-Hispanic-white share, and a median household income of $117,119 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 20 and State Senate District 17.
Akashic
Political twins — state-senate districts
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.
Compare two places, side by side
Twelve curated comparisons line up election history, demographics, and the divergence story for two places at a glance. Browse all comparisons → · Or open the source-auditable district brief for electoral baseline, electorate, current-cycle coverage, geography, official dates, and methodology. Open campaign intelligence report →
Cite this page
All citations released under CC BY 4.0. Attribution: Akashic Intelligence.
Hawaii 21st State Senate District. Akashic. https://akashic.app/sld-upper/15021/. Accessed May 20, 2026. License: CC BY 4.0.
How did Hawaii 21st State Senate District vote in 2024?
In 2024, Hawaii 21st State Senate District voted Republican by 4.2 points (R+4.2), carried by the Republican candidate. Out of 19,625 votes cast, 9,233 went Democratic and 10,054 went Republican.
When did Hawaii 21st State Senate District last vote Democratic?
The most recent presidential election in which Hawaii 21st State Senate District voted Democratic was 2020.
How many people live in Hawaii 21st State Senate District?
Hawaii 21st State Senate District has a population of 59,486 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Hawaii 21st State Senate District?
Median household income in Hawaii 21st State Senate District is $117,119 — above the national median of $80,734. The Hawaii state median is $100,389.
What is the political history of Hawaii 21st State Senate District?
Akashic tracks 38 presidential elections in Hawaii 21st State Senate District from 1876 to 2024. Of those, 7 went Democratic and 10 went Republican.