California's 12th congressional district (CA-12) is a House of Representatives seat located in the East Bay region of the San Francisco Bay Area. It currently includes the cities of Oakland, Berkeley, and San Leandro, along with several unincorporated communities in Alameda County. The district has a strong Democratic lean, with a Cook Partisan Voting Index (PVI) of D+40, making it one of the most reliably Democratic districts in the nation. The 2026 election for this seat is noteworthy because the current representative, Barbara Lee, has announced she will not seek re-election, opting instead to run for the U.S. Senate. This has created an open-seat race, which is rare in such a heavily Democratic district and has attracted a crowded field of candidates from within the party. The primary election for California's congressional seats is scheduled for June 2, 2026, under the state's top-two primary system. In this system, all candidates, regardless of party affiliation, appear on the same ballot, and the top two vote-getters advance to the general election, which will be held on November 3, 2026. Because the district is so heavily Democratic, the general election is expected to be a contest between two Democrats, and the winner of the primary is often considered the de facto winner in November. However, the outcome of the primary is far from certain, with several well-known local politicians and community figures vying for the seat. The race has drawn national attention because it will help determine the balance of power in the House of Representatives, where Democrats are hoping to regain the majority in the 2026 midterm elections. The Cook Political Report rates the general election as 'Solid Democratic,' but the primary is considered highly competitive. The candidates include state senator Nancy Skinner, former Oakland mayor Libby Schaaf, and Berkeley mayor Jesse Arreguín, among others. Each brings a distinct political profile and base of support, making the primary a microcosm of the broader progressive-versus-moderate divide within the California Democratic Party. Interest in this race is also fueled by the potential for historic firsts and the influence of money in politics. The candidates have raised significant funds, with outside groups already spending on advertising. The outcome of this race will likely shape the policy priorities of the district for years to come, from housing and homelessness to climate change and criminal justice reform. For political observers and residents alike, the CA-12 race is a bellwether for the direction of the Democratic Party in the post-Lee era.

Historical Context

California's 12th congressional district has a long history of progressive representation. The seat was held by Ron Dellums from 1971 to 1998, and Dellums was a founder of the Congressional Black Caucus and a leading anti-war voice. When Dellums retired, Barbara Lee won a special election in 1998 and has held the seat ever since. Lee has been a prominent progressive, known for her opposition to the Iraq War and her advocacy for global health and human rights. Her decision to run for the Senate in 2026 has opened the seat for the first time in nearly three decades, creating a rare open-seat race in a district that has not seen a competitive general election in years. The district's boundaries have changed over the years due to redistricting. In the 2020 redistricting cycle, the district was redrawn to include more of Oakland and Berkeley, while losing some areas that are now part of other districts. The current configuration was used for the 2022 and 2024 elections, and it remains in effect for 2026. The district's demographics are diverse, with a significant African American population in Oakland, a large white progressive population in Berkeley, and a growing Asian American and Latino population. This diversity shapes the political dynamics of the primary, as candidates must appeal to a broad coalition of voters. Historically, the top-two primary system has often led to same-party general elections in California. In heavily Democratic districts like CA-12, the primary is the de facto election. In 2022, for example, the general election in CA-12 was between Lee and a Republican, but Lee won with over 90% of the vote. In 2026, with no incumbent, the primary will be the decisive contest, and the top two candidates will likely be Democrats, meaning the general election will be a foregone conclusion. The last time this district had a competitive primary was in 1998, when Lee won a crowded field to succeed Dellums.