- Lead
- 54,838
- Total
- 235,628
- vs nation
- D+24.7
California 66th State House District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 70,995
- Total
- 260,340
- vs nation
- D+22.8
- Lead
- 52,607
- Total
- 211,851
- vs nation
- D+22.7
- Lead
- 29,130
- Total
- 201,020
- vs nation
- D+10.6
- Lead
- 26,604
- Total
- 210,975
- vs nation
- D+5.3
- Lead
- 4,421
- Total
- 200,399
- vs nation
- D+0.3
- Lead
- 4,793
- Total
- 175,959
- vs nation
- D+2.2
- Lead
- 2,733
- Total
- 158,894
- vs nation
- R+6.8
Key facts
- 2024 presidential margin
- D+23.3MIT Election Lab
- Population
- 472,0382024 5-year
- Population density
- 6,236 / sq mi2024 5-year · TIGER/Line
- Land area
- 75.7 sq miTIGER/Line
- Median household income
- $130,1842024 5-year
- White (non-Hispanic)
- 43.9%2024 5-year
- Black
- 4.2%2024 5-year
- Hispanic / Latino
- 21.4%2024 5-year
- Peak Democratic margin
- D+27.3 in 2020MIT Election Lab
- Peak Republican margin
- R+72.6 in 1904MIT Election Lab
- Most similar
- Assembly District 41, CA · twin score 93.2
presidential history
Party record book
California 66th State House District · the strongest Democratic and Republican presidential performances recorded here, measured three ways.
1892–2024 (partial returns from 1876) · 38 presidential cycles · 38 with a vote-share denominator · 34 with a national benchmark
Highest vote share
Largest share of the presidential candidate vote cast here.
Democratic
Joe Biden2020
62.5%
162,667 votes · D+27.3 · modeled estimate
Runner-up · Kamala Harris, 2024 · 60.0%
Republican
Theodore Roosevelt1904
81.4%
3,312 votes · R+72.6 · modeled estimate
Runner-up · Herbert Hoover, 1928 · 80.4%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
162,667votes
62.5% of the vote · D+27.3 · modeled estimate
Runner-up · Kamala Harris, 2024 · 141,268 votes
Republican
Richard Nixon1972
145,691votes
68.8% of the vote · R+40.3 · modeled estimate
Runner-up · Ronald Reagan, 1984 · 133,577 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
+24.7pts D vs U.S.
Place D+23.3 · U.S. R+1.5 · modeled estimate
Runner-up · Joe Biden, 2020 · +22.8 pts
Republican
Theodore Roosevelt1904
+52.9pts R vs U.S.
Place R+72.6 · U.S. R+19.7 · modeled estimate
Runner-up · Benjamin Harrison, 1892 · +51.2 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.
Assembly District 66 covers much of Long Beach, where a diverse, working-class electorate tied to one of the nation's busiest ports has delivered Democratic presidential margins exceeding 20 points in recent cycles.
Across the recorded series it reached a Democratic high of 27.3 points in 2020 and a Republican high of 72.6 points in 1904. Between 2020 and 2024 the district moved 4.0 points toward the Republican candidate; the 2024 margin was 23.3 points.
A population of 472,038, a 44% non-Hispanic-white share, and a median household income of $130,184 describe the district. The district's voting pattern over the last decade is most similar to that of Assembly District 41 and Assembly District 16.
The state-house 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 →
California 66th State House District. Akashic. https://akashic.app/sld-lower/06066/. Accessed May 20, 2026. License: CC BY 4.0.