California's New District Maps Could Flip Control of the US House

California, the most populous US state, is set to play an important role in the midterm elections, because new congressional district maps introduced there could flip control of the House of Representatives to the Democrats. President Donald Trump's Republican Party currently holds a slim majority in the House.

The election will be held on Tuesday, November 3. California polls will be open from 7am to 8pm, and mail ballots must be postmarked by election day.

The House is divided into 435 districts, each represented by one member of Congress. While districts are populated equally, their boundaries are set by states, and drawing those maps to advantage one party is known as partisan redistricting.

California Governor Gavin Newsom first proposed a one-time statewide redistricting effort after seven Republican-led states redrew their maps to secure seats for Republicans. Although California had banned partisan redistricting, Newsom pitched the idea as an unfortunate but necessary retaliatory measure.

Voters approved the plan in a 2025 ballot measure, Proposition 50, which temporarily suspended the state's nonpartisan redistricting commission until 2030. The new maps make several Republican strongholds more competitive for Democrats, and the initiative aims to net at least five additional Democratic seats in a House where Republicans hold a four-seat majority.

California has 52 members in the House of Representatives, the most of any state, with Republicans holding just eight of the seats.

One of the most closely watched races is the 22nd congressional district in the agriculture-rich Central Valley, redrawn under Proposition 50 into a contentious contest in a former Republican stronghold. Incumbent Republican Representative David Valadao is locked in a tight race with Democratic challenger Randy Villegas, who has attacked him over the rising cost of living, healthcare and Trump's immigration crackdowns, a key issue for the area's immigrant farm-working communities.

The 48th district, which includes parts of San Diego County near the border with Mexico, is also considered highly competitive after its boundaries were redrawn. Longtime Republican Representative Darrell Issa decided to retire after the redistricting, with Republican Jim Desmond and Democratic San Diego Councilmember Marni von Wilpert now vying for the seat.

The redistricting has also had an unexpected impact: two Republican members of Congress, Representatives Ken Calvert and Young Kim, are locked in a bitter race against each other after the redrawn maps put them in the same district.

Vying to replace Governor Newsom are Republican political commentator Steve Hilton and Democrat Xavier Becerra, a former California attorney general and secretary of health and human services during former President Joe Biden's administration. Hilton has attacked Becerra over rising crime and homelessness as well as high fuel prices; according to the American Automobile Association, a gallon of petrol costs $5.95 in California compared with $4.22 nationally. A recent Emerson poll showed Becerra ahead by 27 points.

Voters will also weigh in on policy questions, including the most contentious, Proposition 40, a one-time tax on billionaires to help fund healthcare and education. According to CalMatters, the tax would apply to about 200 of the wealthiest people in California; KQED reports that powerful industries and tech titans have poured more than $152m into fighting the measure, compared with $33m raised in support.

Google cofounder Sergey Brin has given more than $102m to defeat Proposition 40, and Propositions 41 and 42 would effectively nullify it if approved. Another measure, Proposition 39, would require Californians to show government-issued IDs in order to vote.