Riding profile

CA-4

US House district — CA · Mixed · us ca

The question

CA-4: a safe seat for the Democrats?

Current forecast

Democrat

Safe

Probability
100%
Mean margin (pts)
26.6
P(close race)
0%

Projected vote share

Projection by party

  • Democrat 63.3%
  • Republican 36.7%

Watch list

The tightest races

Smallest projected margin. Open one for the numbers.

  1. FL-22Democrat68 %1.1 pt margin
  2. AZ-2Republican57 %1.1 pt margin
  3. OH-10Democrat60 %1.1 pt margin

In context

How this riding stacks up

Democrat Republican
HereCA-4 63.3%36.7%
National averageUnited States 54.3% +9.0 44.9% −8.2

Nationwide averages computed across the 435 riding-level projections (unweighted mean).

Projection track

How the projection has moved

Editorial read

CA-4, a mixed riding in CA, elected a member with the Republicans in the previous cycle, with a 29-point margin. The Vote-Scope model projects the Democrats ahead at 63% vote share, against 37% for the Republicans, and the probability of a close race is negligible.

Sitting member

THOMPSON, MIKE MR.

Sits with Democrat

Primary race

Primary results

Held Jun 2, 2026 · Certified official result

Top-two primary

Advanced to the general election

Mike Thompson 41.0%

84,753 votes

Advanced to the general election

Eric Jones 22.2%

45,992 votes

Official source →

Who's running

The candidates

Declared and on-ballot candidates for the upcoming election.

  • Democrat Incumbent

    Thompson, Mike Mr.

  • Democrat Challenger

    Jones, Eric

Previous election · 2024

Won by
Republican
Margin
29.3 pts
Margin shift vs current projection
-2.6 pts

Redistricting impact

Where these voters came from

This district was redrawn under the 2025-2026 mid-decade redistricting. Composition by inherited old-district share:

  • Congressional District 4 (06004) 45%
  • Congressional District 1 (06001) 40%
  • Congressional District 3 (06003) 13%

Around the region

Nearby ridings

Tone only — pick a riding to see the numbers.

Last model run
Cycle
us_house_2026