- Lead
- 46,647
- Total
- 380,949
- vs nation
- R+10.8
California 40th Congressional District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 30,460
- Total
- 396,997
- vs nation
- R+12.1
- Lead
- 41,391
- Total
- 304,058
- vs nation
- R+15.7
- Lead
- 62,785
- Total
- 280,322
- vs nation
- R+26.3
- Lead
- 57,727
- Total
- 278,423
- vs nation
- R+28.0
- Lead
- 98,292
- Total
- 258,731
- vs nation
- R+35.5
- Lead
- 66,288
- Total
- 217,054
- vs nation
- R+31.1
- Lead
- 50,139
- Total
- 188,700
- vs nation
- R+35.1
Key facts
- 2024 presidential margin
- R+12.2MIT Election Lab
- Population
- 757,5232024 5-year
- Population density
- 1,006 / sq mi2024 5-year · TIGER/Line
- Land area
- 753 sq miTIGER/Line
- Median household income
- $114,8132024 5-year
- White (non-Hispanic)
- 47.3%2024 5-year
- Black
- 4.1%2024 5-year
- Hispanic / Latino
- 32.1%2024 5-year
- Peak Democratic margin
- D+23.8 in 1912MIT Election Lab
- Peak Republican margin
- R+70.1 in 1928MIT Election Lab
- Most similar
- Congressional District 47, CA · twin score 79.1
presidential history
Party record book
California 40th Congressional 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
45.2%
179,442 votes · R+7.7 · modeled estimate
Runner-up · Kamala Harris, 2024 · 42.4%
Republican
Herbert Hoover1928
84.3%
9,275 votes · R+70.1 · modeled estimate
Runner-up · Warren G. Harding, 1920 · 78.2%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
179,442votes
45.2% of the vote · R+7.7 · modeled estimate
Runner-up · Kamala Harris, 2024 · 161,484 votes
Republican
Donald Trump2020
209,902votes
52.9% of the vote · R+7.7 · modeled estimate
Runner-up · Donald Trump, 2024 · 208,131 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
Woodrow Wilson1912
+4.2pts D vs U.S.
Place D+23.8 · U.S. D+19.5 · a third-party candidate carried the Place · modeled estimate
Runner-up · Kamala Harris, 2024 · −10.8 pts
Republican
Herbert Hoover1928
+52.7pts R vs U.S.
Place R+70.1 · U.S. R+17.5 · modeled estimate
Runner-up · Charles E. Hughes, 1916 · +45.8 pts
Current officeholders
Federal officeholders only. State and local officeholders are planned for the next data pass.
Senate and governor results are in the Office selector at the top of this page.
U.S. House
Each result reflects the U.S. House district as it was drawn for that election; redistricting has redrawn these lines over time, so they can differ from the current 120th-Congress district shown on the map above.
CA-40 covers dense urban communities in Los Angeles County where Democratic presidential candidates have routinely posted margins above 30 points, reflecting a heavily Latino and working-class electorate with consistently high partisan loyalty.
Across the recorded series it reached a Democratic high of 23.8 points in 1912 and a Republican high of 70.1 points in 1928. Between 2020 and 2024 the district moved 4.6 points toward the Republican candidate; the 2024 margin was 12.2 points.
A population of 757,523, a 47% non-Hispanic-white share, and a median household income of $114,813 describe the district. The district's voting pattern over the last decade is most similar to that of Congressional District 47 and Congressional District 22.
The congressional 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 40th Congressional District. Akashic. https://akashic.app/cd/0640/. Accessed May 20, 2026. License: CC BY 4.0.