99chambers

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

California's 1st District

A district of about 728,000 people, 27% Hispanic, 29% of adults with a bachelor's degree. It votes D+14.1 relative to the nation for president.

Mike McGuire (D) · from Jan 3, 2027Flipped in 2026Next election Nov 7, 2028The 2026 race →
CA-1

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+14.1147th most
Democratic
Most DemocraticMost Republican218th seat · the majority line12113734431516173036442914819101832282425251465041263843194273339CA-149273547321625451348224023520

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+10.5

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-1.

Adults with a bachelor's degree29% 31st pct · 34th of 52 in CA

Lower than 69% of seats.

White adults without a degree44% 64th pct · 1st of 52 in CA

Higher than 64% of seats.

Hispanic residents27% 79th pct · 34th of 52 in CA

Higher than 79% of seats.

Black residents2% 9th pct · 48th of 52 in CA

Lower than 91% of seats.

Asian residents4% 55th pct · 51st of 52 in CA

Higher than 55% of seats.

People per square mile40 9th pct · 49th of 52 in CA

Less dense than 91% 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.

OR-4
33% college gradsD+12.9Held DWA-6
35% college gradsD+19.4Held DMA-1
32% college gradsD+16.0Held DCA-4
31% Hispanic · 34% college gradsD+16.6Held 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. Mike McGuire (D)
    2027– · Won 2026 by 10.5

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