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California's 21st Congressional District
The current officeholder, the 2024 result, and a precinct-level model you can run yourself — built from how California actually voted.
Model California's 21st Congressional District →
Current officeholder
Jim Costa Democratic
2024 result
Democratic D+5.2
2024 votes cast
195,261
Office
U.S. House
Who lives in this district
This district is home to about 757,752 people, median age 31.6, median household income $62,084.
Population
757,752
Median age
31.6
Median household income
$62,084
Bachelor's degree or higher
16.5%
Race & ethnicity: White 18.8% · Black 4.7% · Hispanic 64.3% · Asian 9.5%
Source: U.S. Census Bureau, 2019–2023 American Community Survey (5-year).
Precinct results — 2024 general
582 precincts reported in California's 21st Congressional District's 2024 general election. The twenty largest:
| Precinct | Winner | Margin | Votes |
|---|---|---|---|
| 06019-0000413A | Democratic | D+22.4 | 2,644 |
| 06019-0000239A | Democratic | D+8.4 | 2,623 |
| 06019-0000458A | Democratic | D+1.5 | 2,235 |
| 06019-0000203A | Democratic | D+0.5 | 2,059 |
| 06019-0000343A | Democratic | D+48.3 | 2,004 |
| 06019-0000387A | Democratic | D+43.7 | 1,986 |
| 06019-0000275A | Democratic | D+17.7 | 1,918 |
| 06019-0000369A | Democratic | D+45.9 | 1,915 |
| 06019-0000344A | Democratic | D+46.2 | 1,847 |
| 06019-0000097A | Democratic | D+22.4 | 1,793 |
| 06019-0000329A | Democratic | D+15.9 | 1,783 |
| 06019-0000104A | Democratic | D+4.2 | 1,775 |
| 06107-3063002A | Republican | R+32.8 | 1,737 |
| 06019-0000438A | Democratic | D+3.1 | 1,714 |
| 06019-0000202A | Democratic | D+8.0 | 1,647 |
| 06019-0000396A | Democratic | D+32.4 | 1,588 |
| 06019-0000320A | Democratic | D+28.5 | 1,583 |
| 06019-0000394A | Democratic | D+29.6 | 1,492 |
| 06019-0000237A | Democratic | D+8.1 | 1,480 |
| 06019-0000397A | Democratic | D+27.1 | 1,440 |
All 582 precincts are modelable — open the race in the simulator and drill to precinct grain.
Find your district
Enter a ZIP code or a district (e.g. NC-4) to find your U.S. House district and who represents it.
Model California's 21st Congressional District in five steps
- Set the candidates. Name the contenders for the California's 21st Congressional District (or keep the generic Democrat / Republican defaults). The map starts from the canonical mixed-grain 2024 presidential baseline.
- Apply a swing. Move vote share statewide, or by demographic cohort, with a slider. The map and the running tally recompute instantly.
- Model turnout. Mobilize or depress turnout for any group — turnout and persuasion are modeled separately, the way a real campaign thinks about them.
- Explore local geography. Zoom from the state through counties to the finest supported reporting grain and adjust the places available in the model.
- Roll up & share. Roll the result up to chamber control, then share the exact versioned scenario.
Open California's 21st Congressional District in the simulator →