- Lead
- 40,594
- Total
- 283,981
- vs nation
- D+15.8
California 42nd State House District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 58,979
- Total
- 310,210
- vs nation
- D+14.6
- Lead
- 42,309
- Total
- 261,950
- vs nation
- D+14.1
- Lead
- 13,632
- Total
- 245,445
- vs nation
- D+1.7
- Lead
- 21,801
- Total
- 254,672
- vs nation
- D+1.3
- Lead
- 16,233
- Total
- 238,303
- vs nation
- R+4.4
- Lead
- 7,660
- Total
- 212,898
- vs nation
- R+4.1
- Lead
- 4,326
- Total
- 188,010
- vs nation
- R+10.8
Key facts
- 2024 presidential margin
- D+14.3MIT Election Lab
- Population
- 516,1022024 5-year
- Population density
- 957 / sq mi2024 5-year · TIGER/Line
- Land area
- 540 sq miTIGER/Line
- Median household income
- $142,8402024 5-year
- White (non-Hispanic)
- 23.4%2024 5-year
- Black
- 0.5%2024 5-year
- Hispanic / Latino
- 2.5%2024 5-year
- Peak Democratic margin
- D+33.8 in 1912MIT Election Lab
- Peak Republican margin
- R+63.7 in 1924MIT Election Lab
- Most similar
- Assembly District 66, CA · twin score 83.5
presidential history
Party record book
California 42nd 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
Franklin D. Roosevelt1936
59.9%
23,547 votes · D+21.0 · modeled estimate
Runner-up · Joe Biden, 2020 · 58.5%
Republican
Warren G. Harding1920
76.2%
8,584 votes · R+59.2 · modeled estimate
Runner-up · Herbert Hoover, 1928 · 74.5%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
181,541votes
58.5% of the vote · D+19.0 · modeled estimate
Runner-up · Kamala Harris, 2024 · 159,723 votes
Republican
Ronald Reagan1984
131,175votes
69.3% of the vote · R+39.7 · modeled estimate
Runner-up · George W. Bush, 2004 · 125,852 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
+15.8pts D vs U.S.
Place D+14.3 · U.S. R+1.5 · modeled estimate
Runner-up · Joe Biden, 2020 · +14.6 pts
Republican
Calvin Coolidge1924
+38.5pts R vs U.S.
Place R+63.7 · U.S. R+25.2 · modeled estimate
Runner-up · Herbert Hoover, 1928 · +33.2 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.
The district recorded a Democratic presidential margin of D+14.2 in 2024, compared with D+8.6 in 2008. No racial group formed a majority of its residents in the 2024 ACS 5-year, with Hispanic or Latino residents at 47.5%.
Across the recorded series it reached a Democratic high of 33.8 points in 1912 and a Republican high of 63.7 points in 1924. Between 2020 and 2024 the district moved 4.7 points toward the Republican candidate; the 2024 margin was 14.3 points.
A population of 516,102, a 23% non-Hispanic-white share, and a median household income of $142,840 describe the district. The district's voting pattern over the last decade is most similar to that of Assembly District 66 and Assembly District 41.
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 42nd State House District. Akashic. https://akashic.app/sld-lower/06042/. Accessed May 20, 2026. License: CC BY 4.0.