Southern California has entered the 2026 elections with new congressional district maps already in place, and the Los Angeles mayoral race is unfolding under the same redistricting moment that changed several House seats. California voters approved a mid-cycle redistricting plan last year, after courts allowed it and a special election was called in late August last year.
The change now shows up in three districts that will help shape the statewide House result: California’s 27th Congressional District, California’s 42nd Congressional District and California’s 48th Congressional District. The June primary election already used the new maps, so the current general election is the first full test of how those lines and voter-registration shifts hold up in a larger electorate.
California’s 27th Congressional District
California’s 27th Congressional District now represents Lancaster, Palmdale and Santa Clarita in the Antelope and Santa Clarita valleys, while losing Acton and Quartz Hill and picking up Reseda and Lake Balboa. Democrats in California’s 27th Congressional District now hold a 15-percentage-point voter registration advantage over Republicans, with more than 42% of registered voters identified as Democrats, 23% as Republicans and 23% as no party preference.
That is a sharper political edge than the district had before redistricting. The Cook Political Report describes the seat as “solidly Democratic,” even though the district was once competitive, which is the clearest sign that the new lines did more than redraw a map.
Orange County and the 42nd District
Orange County was divided up into eight districts under the new maps, and two of those districts, the 38th District and 41st District, mostly encompass communities to the north in L.A. County while only picking up a few of Orange County’s cities. California’s 42nd Congressional District still includes Long Beach, and now spans down the coast to pick up Huntington Beach and part of Newport Beach.
The registration split there points in the same direction as the Cook Political Report ranking. Nearly 41% of registered voters in California’s 42nd Congressional District are Democrats, compared with 30% Republicans and 21.5% no party preference. The Cook Political Report ranks the district as “solid” for Democrats, so the new lines left it within the party’s safer range even after adding new coastal territory.
California’s 48th Congressional District
California’s 48th Congressional District spans Riverside and San Diego counties and inherited deep blue Palm Springs after redistricting. Election experts have said the district has become “more competitive,” and the registration numbers show why: before redistricting, 41% of registered voters were Republican, 29% were Democratic and 21% were no party preference.
That leaves the district in a different position from California’s 27th Congressional District and California’s 42nd Congressional District. One seat moved toward a solid Democratic edge, one stayed there, and one became harder to read, which is the practical effect readers should watch as the 2026 general election continues to develop across Southern California.
