Proposition 40 supporters have secured another major endorsement, this time from the Los Angeles County Democratic Party, the largest local Democratic Party organization in California and the country.
The Los Angeles County Democratic Party represents more than 2.9 million registered Democrats. Its endorsement gives the California Billionaire Tax campaign another significant boost as supporters work to build momentum ahead of the election.
The endorsement, announced Thursday, comes shortly after Prop. 40 received backing from the California Democratic Party and the California Federation of Labor. Democratic Party organizations in dozens of counties across California have also endorsed the measure.
READ: California Billionaire Tax: Healthcare workers’ union endorses Proposition 40 (September 15, 2026)
“Today’s endorsement further clarifies that the Democratic party is unified behind Prop 40,” said Suzanne Jimenez, chief of staff at SEIU-United Healthcare Workers West.
Prop. 40 supporters said they overcame extensive lobbying efforts by high-priced consultants working on behalf of billionaires before securing the Los Angeles County Democratic Party endorsement.
Supporters have also pushed back against claims that Democrats are divided over the measure. They point to polling that they say shows strong support for the California Billionaire Tax among key groups. According to figures cited by the campaign, 80% of Democrats, 70% of union members, 63% of teachers and 63% of healthcare workers support Prop. 40.
The initiative also gained a place on the ballot after supporters submitted more than 1.6 million signatures from Californians across the state. That figure was nearly twice the number required to qualify the measure, which supporters describe as one of the strongest citizen-led ballot qualification efforts in California history.
Prop. 40 has attracted endorsements from hundreds of elected officials, labor unions and community organizations. Those backing the measure include U.S. Senator Bernie Sanders, Representative Ro Khanna, Rep. Judy Chu, the California Democratic Party, the California Federation of Labor, the California Nurses Association, the California Young Democrats and the California State Parent Teacher Association.
Other supporters include Teamsters California, AFSCME California, SEIU-UHW, Committee of Interns and Residents / SEIU, UNITE HERE Local 11, UNITE HERE Local 30, AFT Local 1521, Disability Voices United, Our Revolution California, Oxfam America and Color of Change, along with many other organizations.
At the center of the campaign is the California Billionaire Tax Act, which proposes a one-time emergency tax on the wealth of the state’s ultra-high-net-worth billionaires.
According to supporters, the revenue generated through the measure would be used to safeguard Medi-Cal, help keep hospitals and emergency rooms open, expand food assistance and support public education.
The initiative comes in response to federal healthcare cuts under HR1, which supporters say threaten healthcare access and economic stability for millions of Californians.
READ: Ro Khanna criticizes Trump’s taxes, tariffs, and war policies, says Democrats need to be in power (July 30, 2026)
Unlike income and sales taxes, which are imposed on realized income or transactions, a wealth tax is assessed on the value of assets held by an individual.
Under Prop. 40, the proposed tax would apply to various assets owned by billionaires. These include commodities, ownership interests in companies with publicly traded securities, ownership interests in private companies, real estate and artwork.
The latest endorsement adds the Los Angeles County Democratic Party to an expanding list of Democratic organizations, labor groups, elected officials and community organizations supporting the measure as California voters prepare to decide the fate of Prop. 40.