Response review

I'll look up the current U.S. Representative for California's 4th congressional district.
Your U.S. Representative for California's 4th congressional district (CA-04) is **Mike Thompson**, a Democrat.


California's 4th congressional district is located in the northwestern part of the state, and includes all of Lake County and Napa County, most of Yolo County, and parts of Solano County and Sonoma County. Major cities in the district include Davis, Woodland, Napa, Vacaville, and most of Santa Rosa, and it is solidly Democratic, represented by Mike Thompson.
 
As of the current makeup, California's 4th Congressional District in the United States House of Representatives is represented by Mike Thompson (D).


A couple of notes:
- 
As of the 2020 Census, California representatives represented an average of 761,091 residents.

- California recently passed a redistricting measure. 
This Congressional district was established by the voters of California with the passage of Proposition 50 (2025) on November 4, 2025 and will go into effect after the November 2026 elections and upon seating of the 120th Congress, January 3, 2027.
 So the district boundaries you're in today are the ones currently in effect, with new lines taking hold after the 2026 elections.

If you'd like, I can help you confirm your exact district based on your address, since district boundaries can be complex.