Five seats.
One real race.
DemocraticRepublicanNo party preferenceOtherRegistration as of the June 2, 2026 primary, whole district
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One seat moved 19 points. Three others gave up votes to make it happen.
The same 2024 presidential votes, counted two ways: under the 2022–2024 district lines and under the new lines voters approved in November 2025. Democratic voters were moved out of safe seats (50, 51 and 52) and into the 48th, which went from Trump +15.7 to Harris +3.3.
Old lines (2024 election)New lines (2026 election)
Only the 48th is close on any measure
Each mark is one measure of lean for the whole district, in percentage points. Left of center leans Democratic, right leans Republican.
The raters call the 48th Lean Democratic. The other four are safe.
- The ratings come from the raters' published tables (Cook Sep 25, Sabato Sep 29, Inside Elections Oct 1, 2026), as compiled on Wikipedia because the raters' own sites block automated reads.
- Primary voters are older and more partisan than November voters. All-Democratic vs all-Republican primary totals point the right way in most years but miss by several points.
- Fundraising figures run through June 30, 2026. Third-quarter reports are due to the FEC on Oct 15.
- About half of the 48th's votes come from Riverside County (Palm Springs and the Coachella Valley), which this map includes.
Use the map to answer these.
- Switch the map to Prop 50. Which district voted most strongly for the new map? Which voted least? Why might that be?
- The 50th, 51st and 52nd each became less Democratic under the new lines, while the 48th became much more Democratic. Use the words packing and cracking to explain what the mapmakers did.
- Zoom in on your own neighborhood. Which district are you in? How did your precinct vote in 2024, and how does it compare with the whole district?
- Compare the June 2026 House primary layer with the 2024 President layer for the 48th. Which looks better for each candidate, and why might a primary electorate differ from a November one?
- Desmond and von Wilpert each raised more than $2 million by June 30. The Republicans in the other four seats raised almost nothing. What does that tell you about where money goes in House races?
Method and sources
- District lines: built by merging the precincts the Secretary of State assigned to each district for the June 2, 2026 primary, the first election held under the Prop 50 map. Only CA-48 (with Riverside County) and CA-49 (with Orange County) cross the county line. Imperial County is in CA-25, which has no San Diego territory.
- Results and registration: Statewide Database, UC Berkeley (statewidedatabase.org) precinct files for San Diego, Riverside and Orange counties: Nov 2024 general, Nov 2025 special (Prop 50) and June 2026 primary. Nov 2024 and Nov 2025 precincts are placed in the new district that holds most of their land. San Diego County totals land within 0.1% of the county's precinct totals.
- Certified primary results: California Secretary of State, Statement of Vote, U.S. Representative (certified July 10, 2026). Prop 50: Statement of Vote, Nov 4, 2025 special.
- Margins are two-party: (Republican − Democrat) ÷ (Republican + Democrat). Primary measures sum every Democratic candidate against every Republican candidate. Registration margin is Republican minus Democratic registration as a share of all voters.
- Money: FEC candidate totals through June 30, 2026. Poll: SurveyUSA for KGTV/San Diego Union-Tribune, Aug 27–Sep 1, 2026, 522 likely voters, ±5.2 (10News). Background: CalMatters, CalMatters on Issa's retirement, KQED.