99chambers

U.S. House seat · lines in effect since 2026

California's 31st District

A district of about 727,000 people, 57% Hispanic, 29% of adults with a bachelor's degree. It votes D+15.9 relative to the nation for president.

Gilbert Ray Cisneros, Jr. (D) · since Jan 3, 2025Next election Nov 7, 2028The 2026 race →
CA-31

Source: 2026 results: California Secretary of State; boundaries: Census Bureau TIGER/LineUpdated Nov 7, 2026, 3:01 PM ET

Where it sits among all 435 seats

Every U.S. House seat by partisan lean, from most Democratic to most Republican. Lean is the seat's presidential vote on current lines, relative to the nation.

D+15.9139th most
Democratic
Most DemocraticMost Republican218th seat · the majority line1211373443151617303644291481910183228242525146504126384CA-3194273339149273547321625451348224023520

Labels below the bar mark 51 other seats in California.

Source: 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET

Every race on these lines

Results recomputed from precinct returns as if today's boundaries had always existed, so years compare like for like.

2026
U.S. HouseD+31.1

Outlined: the race for this seat itselfBlank: no race that year

Source: 99chambers results archive: precinct results allocated to current lines; 2026: California Secretary of StateUpdated Nov 7, 2026, 3:01 PM ET

Who lives here, compared

Grey bars show the spread of all 435 seats. Small marks are other seats in California. The black marker is CA-31.

Adults with a bachelor's degree29% 33rd pct · 31st of 52 in CA

Lower than 67% of seats.

White adults without a degree13% 10th pct · 39th of 52 in CA

Lower than 90% of seats.

Hispanic residents57% 93rd pct · 17th of 52 in CA

Higher than 93% of seats.

Black residents4% 26th pct · 31st of 52 in CA

Lower than 74% of seats.

Asian residents18% 95th pct · 14th of 52 in CA

Higher than 95% of seats.

People per square mile4,287 90th pct · 11th of 52 in CA

Denser than 90% of seats.

Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current linesUpdated Oct 13, 2026, 5:06 AM ET

Seats most like this one

Nearest seats on demographics, density and lean.

CA-35
60% Hispanic · 28% college gradsD+12.0Held DCA-38
58% Hispanic · 29% college gradsD+16.7Held DCA-46
64% Hispanic · 24% college gradsD+19.7Held DCA-41
61% Hispanic · 29% college gradsD+17.6Held D

Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current lines; 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET

Who has held it

These lines took effect in 2026.

  1. Gil Cisneros (D)
    2027– · Won 2026 by 31.1

Source: Past results: 99chambers results archive (MEDSL, Klarner, state election offices)