California 31st Congressional District: New American district. In 2024, voted D+17%. Democratic peak: D+37 in 2016.
Key facts
- 2024 presidential margin
- D+17MIT Election Lab
- Political typology
- New AmericanAkashic typology
- Population
- 505,6412024 5-year
- Median household income
- $90,1122024 5-year
- White (non-Hispanic)
- 30.9%2024 5-year
- Black
- 7.7%2024 5-year
- Hispanic / Latino
- 48.4%2024 5-year
- Peak Democratic margin
- D+37 in 2016MIT Election Lab
DW-NOMINATE
Member ideology
D
CISNEROS, Gil
CISNEROS scores -0.46 on the first NOMINATE dimension (−1 most liberal, +1 most conservative).
Predecessors: NAPOLITANO, Grace Flores (2023–2025), AGUILAR, Peter Rey (2021–2023), AGUILAR, Peter Rey (2019–2021), AGUILAR, Peter Rey (2017–2019)
Source · Voteview / Lewis, Poole, Rosenthal et al. (CC-BY).
2024 presidential election
Congressional District 31
HarrisD+17
Constituent county margins for Congressional District 31, CAOne cell per constituent county, colored by 2024 presidential margin from deep red (Republican) through neutral to deep blue (Democratic), ordered bluest first.
How it voted
Share of the 2024 vote
| Kamala Harris ✓Democratic | 56.9% | 151,568 |
|---|---|---|
| Donald TrumpRepublican | 40.0% | 106,580 |
| OtherAll other candidates | 3.0% | 8,016 |
D+60R+60
1 counties, each filled by 2024 D-vs-R margin.
presidential history
Presidential margin, 2008–2024
Democratic minus Republican, by election
| Year | Margin (D minus R) |
|---|---|
| 2008 | +26.9% |
| 2012 | +31.5% |
| 2016 | +37.2% |
| 2020 | +31.1% |
| 2024 | +16.9% |
DemocraticRepublican
5 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| D | 151,568 | 106,580 | 266,164 | ||
| D | 197,939 | 102,628 | 306,930 | ||
| D | 156,317 | 67,881 | 238,018 | ||
| D | 142,005 | 74,006 | 216,011 | ||
| D | 142,831 | 82,119 | 225,670 |
Congressional elections · 17 Senate races
U.S. Senate
| Year | Won | D % | R % | Total |
|---|---|---|---|---|
| 2024 | D | 58.9% | 41.1% | 15,348,846 |
| 2022 | D | 61.1% | 38.9% | 10,843,650 |
| 2018 | D | 100.0% | 0.0% | 11,113,364 |
| 2016 | D | 100.0% | 0.0% | 12,244,170 |
| 2012 | D | 62.5% | 37.5% | 12,578,511 |
| 2010 | D | 52.2% | 42.2% | 10,000,160 |
| 2006 | D | 59.4% | 35.0% | 8,541,476 |
| 2004 | D | 57.7% | 37.8% | 12,053,295 |
| 2000 | D | 55.8% | 36.6% | 10,623,608 |
| 1998 | D | 53.1% | 43.0% | 8,311,905 |
| 1994 | D | 46.7% | 44.8% | 8,514,089 |
| 1992 | D | 47.9% | 43.0% | 10,799,703 |
| 1988 | R | 44.0% | 52.8% | 9,743,598 |
| 1986 | D | 49.3% | 47.9% | 7,398,462 |
| 1982 | R | 44.8% | 51.5% | 7,805,450 |
| 1980 | D | 56.5% | 37.1% | 8,324,012 |
| 1976 | R | 46.9% | 50.2% | 7,470,586 |
Demographics
2024 ACS
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
German
4.3%
Irish
3.8%
English
3.8%
American
3.1%
Italian
2.5%
Polish
1.1%
French
1.0%
Source · American Community Survey 5-year estimates, 2024 release. Hispanic/Latino is an ethnicity that overlaps the race categories, so these shares can total more than 100%. Ancestry is a self-reported, multiple-response item; ancestry percentages do not sum to the parent race percentage.
2024 ACS
Age distribution by sex
Median age: 38.2 in this county, 39.1 nationally
Male
Age
Female
85+
75–84
65–74
55–64
45–54
35–44
25–34
18–24
5–17
<5
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Median household income
Inflation-adjusted dollars
$90,112
Congressional District 31 ranks near the middle of US counties.
Congressional District 31$90,112
California$99,122
United States$80,734
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Poverty rate
All persons below federal poverty line
13.7%
Children face moderate poverty.
Children under 1817.6%
Working age (18–64)12.5%
Seniors (65+)15.9%
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Language at home
Population aged 5 and older
44.9%
speak English only
Spanish37.6%
Asian & Pacific Islander10.7%
Other Indo-European5.6%
Other languages1.2%
Source · ACS 5-year estimates, 2024.
2020 religion census
Religious adherents
Adherents per capita by tradition
Source · 2020 US Religion Census. Remaining 49.1% of residents not counted as adherents by any reporting body.
California's 31st district covers a dense stretch of the eastern San Gabriel Valley with a majority-Latino and Asian-American electorate, producing a modest Democratic lean that has narrowed as the region's suburban composition continues to shift.
Across the recorded series it reached a Democratic high of thirty-seven points in 2016. Between 2020 and 2024 the district moved fourteen points toward the Republican candidate; the 2024 margin was seventeen points.
A population of 505,641, a 31% non-Hispanic-white share, and a median household income of $90,112 describe the district.
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 →
Cite this page
All citations released under CC BY 4.0. Attribution: Akashic Intelligence.
Congressional District 31, California. Akashic. https://akashic.app/cd/0631/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
Frequently asked questions
How did Congressional District 31, California vote in 2024?
In 2024, Congressional District 31, California voted Democratic by 16.9 points (D+17), carried by the Democratic candidate. Out of 266,164 votes cast, 151,568 went Democratic and 106,580 went Republican.
What is Congressional District 31, California's political typology?
Akashic places Congressional District 31, California in the "New American" typology. The typology is a data-driven cluster built from vote share, vote swing, race and ethnicity, income, language spoken at home, religion, and ancestry. Across 5 elections in the dataset, the district has voted Democratic 5 times, Republican 0 times, and other 0 times.
How many people live in Congressional District 31, California?
Congressional District 31, California has a population of 505,641 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Congressional District 31, California?
Median household income in Congressional District 31, California is $90,112 — above the national median of $80,734. The California state median is $99,122.
What is the political history of Congressional District 31, California?
Akashic tracks 5 presidential elections in Congressional District 31, California from 2008 to 2024. Of those, 5 went Democratic and 0 went Republican. The district's typology — "New American" — captures where that record, its demographics, and its recent swing place it among American communities.