VOTE YES ON PROP 40
Vote Yes on Prop 40. Join the people and organizations asking California to protect care and make the ultra wealthy contribute toward that public need.
The facts at a glance
The California Nurses Association and California Democratic Party both endorse Prop 40. [1][3]
The California Federation of Labor Unions has endorsed Prop 40 [2]
Bernie Sanders, Ro Khanna, Robert Reich, and Chris Murphy are among the documented supporters below. [4][8]
Healthcare workers are helping lead this effort
SEIU United Healthcare Workers West supports Prop 40 and sponsors the campaign. The campaign also lists the Committee of Interns and Residents / SEIU among its supporters. These are named healthcare-worker organizations—not an anonymous claim that “experts agree.” [4][6]
The reason to act reaches beyond one workplace. The measure will fund care and help preserve the services people need when they are sick or injured. For patients and families, the question is whether help will be available when they need it. [5]
Stand with nurses backing a Yes vote
The California Nurses Association endorses Proposition 40. Its support puts nurses’ voices behind a measure designed to fund coverage, healthcare providers and the services our communities rely on. The initiative explicitly provides funding to prevent or reduce hospital and other healthcare-service closures and cuts. [1][5]
That is the practical choice at the heart of a Yes vote: ask extraordinarily wealthy billionaires to contribute to care, rather than accept the loss of services as inevitable. Read the nurses’ endorsement, then look at the healthcare uses written into the measure.
Labor is connecting healthcare to California’s working families
The California Federation of Labor Unions announced its endorsement on August 4. In the federation’s release, President Lorena Gonzalez argues that billionaires should contribute to hospitals and healthcare programs to offset the federal cuts, and connects Prop 40 to saving lives, protecting healthcare jobs, and keeping hospitals open. [2]
AFSCME California’s PEOPLE Committee, Teamsters California, UNITE HERE Local 11, UNITE HERE Local 30, and AFT Local 1521 have all announced their endorsement of Prop 40. [4][7]
Hear why Sanders, Khanna, Reich, and Murphy support it
In statements published by SEIU-UHW, Bernie Sanders states that the demand for a fair contribution from billionaires is to address people losing access to healthcare. U.S. Senator Chris Murphy describes joining healthcare workers in support and argues that repairing healthcare requires asking the super-wealthy to contribute. Professor and former United States Secretary of Labor Robert Reich makes the case for the one-time tax as a way to fund public needs. [8]
Ro Khanna joined the August 18 San Jose rally in support of Prop 40. He called for putting working people and children’s health insurance ahead of billionaire donors. These are the speakers’ arguments, with their published records linked. [4]
A coalition beyond a single profession or organization
The California Democratic Party’s general-election endorsement document records support for Prop 40. Prop 40’s endorsers also include Disability Voices United, Our Revolution California, Oxfam America, and Color of Change. [3][4]
Each named supporter below has a linked record. A federation’s endorsement is counted as that federation’s position, not as a separate endorsement by every member or affiliated organization.
The support is backed by a proposal you can examine
The evidence pages explain who pays, what the money will fund and how the tax would work. Professors Boll, Saez, and Zucman provide revenue research; Galle, Gamage, and Shanske explain the legal design. The LAO supplies a separate official fiscal assessment. Research authors and agencies are identified as evidence sources, not automatically as endorsers. [9][10][11]
Follow the source links, hear the people supporting this effort, and join them. Vote Yes on Prop 40 to help protect healthcare and ask California’s billionaires to contribute their fair share to the public needs of California.
A few more answers
Is this the complete campaign endorsement list?
No. This is the documented selection used in this evidence library. It does not claim to include every supporter or every endorsement collected by the campaign.
If a university is hosting a paper does that mean it endorses Prop 40?
No. We identify the paper’s authors and publisher separately from documented campaign supporters.
The people and institutions behind the evidence
Working-paper author
Jasper Boll
Coauthor of the 2026 billionaire-wealth and revenue working paper. Its projections are estimates. [9]
Working-paper author and disclosed unpaid design/scoring adviser
Emmanuel Saez
The July 2026 explanatory report identifies Emmanuel Saez with UC Berkeley. He coauthored the revenue paper and discloses unpaid design/scoring advice. [9] [12]
Working-paper author
Gabriel Zucman
Coauthor of the 2026 billionaire-wealth and revenue working paper. [9]
Measure drafter and legal-analysis author
Brian Galle
The July 2026 explanatory report identifies Brian Galle with UC Berkeley. A measure drafter and coauthor of the legal analysis, he also explains the proposal in a Berkeley Law interview. [10] [12] [13]
Measure drafter and legal-analysis author
David Gamage
The July 2026 explanatory report identifies David Gamage with the University of Missouri. He is a measure drafter and coauthor of the legal and valuation analyses. [10] [12] [14]
Measure drafter and legal-analysis author
Darien Shanske
The July 2026 explanatory report identifies Darien Shanske with UC Davis. He is a measure drafter and coauthor of the legal and valuation analyses. [10] [12] [14]
Author of the healthcare-funding jobs scenarios
Laurel Lucia
Authored the April 2025 UC Berkeley Labor Center scenario analysis. The study predates the enacted federal bill. [15]
People and organizations backing a Yes vote
First-party endorsement
California Nurses Association
California Nurses Association supports California Proposition 40 (2026).
Support appears in CNA’s California ballot-measure list. [1]
California Democratic Party
California Democratic Party supports California Proposition 40 (2026).
The statewide party’s published ballot-measure position. [3]
First-party endorsement
California Federation of Labor Unions, AFL-CIO
California Federation of Labor Unions, AFL-CIO supports California Proposition 40 (2026).
The state federation’s endorsement; not a separate endorsement by every affiliated union. [2]
Public support recorded in the federation’s own release
Lorena Gonzalez, President of California Federation of Labor Unions, AFL-CIO
Lorena Gonzalez supports California Proposition 40 (2026).
The federation’s August 4 release quotes her case for billionaire contributions to protect hospitals, lives and healthcare jobs. [2]
SEIU United Healthcare Workers West
SEIU United Healthcare Workers West supports California Proposition 40 (2026).
SEIU-UHW’s position. [6]
Campaign-reported support
U.S. Senator Bernie Sanders
Bernie Sanders supports California Proposition 40 (2026).
Named in the campaign’s August 18 supporter roster. [4]
Campaign-reported support
U.S. Representative Ro Khanna
Ro Khanna supports California Proposition 40 (2026).
The campaign documents Khanna’s participation in the August 18 support rally. [4]
Campaign-reported endorsement
AFSCME California PEOPLE Committee
AFSCME California supports California Proposition 40 (2026).
The March 12 release reports its California PEOPLE endorsement vote. [7]
Campaign-reported support
Committee of Interns and Residents / SEIU
Committee of Interns and Residents / SEIU supports California Proposition 40 (2026).
Named in the campaign’s August 18 supporter roster; Not an inferred position for every SEIU affiliate. [4] [6]
Campaign-reported support
Teamsters California
Teamsters California supports California Proposition 40 (2026).
Representing 250,000 California workers, announced its endorsement in January 2026. [16]
Campaign-reported support
UNITE HERE Local 11
UNITE HERE Local 11 supports California Proposition 40 (2026).
Named in the campaign’s August 18, 2026 supporter roster. [4]
Campaign-reported support
UNITE HERE Local 30
UNITE HERE Local 30 supports California Proposition 40 (2026).
Campaign-reported support
AFT Local 1521
AFT Local 1521 supports California Proposition 40 (2026).
Named in the campaign’s August 18, 2026 supporter roster. [4]
Campaign-reported support
Disability Voices United
Disability Voices United supports California Proposition 40 (2026).
Named in the campaign’s August 18, 2026 supporter roster. [4]
Campaign-reported support
Our Revolution California
Our Revolution California supports California Proposition 40 (2026).
Named in the campaign’s August 18, 2026 supporter roster. [4]
Campaign-reported support
Oxfam America
Oxfam America supports California Proposition 40 (2026).
Campaign-reported support
Color of Change
Color of Change supports California Proposition 40 (2026).
Named in the campaign’s August 18, 2026 supporter roster. [4]
Support reported by SEIU-UHW
Robert Reich, Professor and former U.S. Secretary of Labor
Robert Reich supports California Proposition 40 (2026).
SEIU-UHW publishes a supportive statement attributed to Robert Reich. [8]
Support reported by SEIU-UHW
U.S. Senator Chris Murphy
Chris Murphy supports California Proposition 40 (2026).
SEIU-UHW publishes a supportive statement attributed to Chris Murphy. [8]
Hear more from the people involved
INTERVIEW + READABLE TRANSCRIPT
Professor Brian Galle on “How to Tax the Ultrarich”
A Berkeley Law interview with a full transcript about taxing the ultrarich. Galle distinguishes federal reform from the California proposal he helped draft.
Open the original source →SUPPORTER STATEMENTS
Billionaire Tax Act — Supporters Speak Out
Publishes supportive statements from Robert Reich, Bernie Sanders, and Chris Murphy. These are SEIU-reported statements, not independent recordings verified here.
Open the original source →Keep reading
ENDORSEMENTS
Prop 40 Endorsements
See the full endorsement page →
WHY VOTE YES
Help Keep Hospitals, Clinics and Emergency Rooms Open
Read the detailed page →
WHY VOTE YES
A Billionaire Tax—Not a Tax on Ordinary Paychecks
Read the detailed page →
CHECK THE EVIDENCE
Sources behind this page
Each reference identifies what it establishes. A cited agency or researcher is not automatically a campaign endorser.
01California endorsements
California Nurses Association; hosted by National Nurses United · Undated live roster; checked September 10, 2026 · First-party endorsement
The California Nurses Association’s statewide ballot-measure roster lists support for Prop 40.
Where to look: California Statewide Ballot Measures
https://www.nationalnursesunited.org/california-endorsements
02California Federation of Labor Unions Overwhelmingly Supports Billionaires Tax, Prop 40
California Federation of Labor Unions, AFL-CIO · August 4, 2026 · First-party endorsement
The state federation’s own endorsement announcement. An umbrella organization’s position does not establish separate endorsements by every affiliate.
Where to look:
https://calaborfed.org/press-releases/california-federation-of-labor-unions-overwhelmingly-supports-billionaires-tax-prop-40/
032026 General Election Endorsements & Ballot Measure Positions
California Democratic Party · August 2, 2026 · First-party endorsement
The California Democratic Party’s own ballot-measure positions include support for Prop 40.
Where to look: Ballot-measure positions at the bottom of the single PDF page.
https://cadem.org/wp-content/uploads/2026/08/FINAL-2026-General-Election-Endorsements.pdf
04Rep. Ro Khanna, California Unions Unite on Stage in San Jose for Rally in Support of Prop 40
Yes on 40 · August 18, 2026 · Campaign report
The campaign’s report of the San Jose rally and participating supporters, including Ro Khanna. It also identifies support from Bernie Sanders and CIR/SEIU.
Where to look:
https://yeson40.com/rep-ro-khanna-california-unions-unite-on-stage-in-san-jose-for-rally-in-support-of-popular-prop-40/
05Proposition 40: text of proposed laws
California Secretary of State · 2026 voter guide · Proposed law
The actual proposed rules on taxpayer eligibility, valuation, payments, spending, and reporting. Tax payments begin in 2027; audit authority and special trust rules remain. Section 50310 governs possible amendments.
Where to look: Gov. Code §16355, PDF pp. 4–5; Rev. & Tax. Code §§50301, 50303–50304, 50308–50312, PDF pp. 5–13.
https://vig.cdn.sos.ca.gov/2026/general/pdf/prop40-text-proposed-laws.pdf
06Prop 40: The California Billionaire Tax Act
SEIU United Healthcare Workers West · Undated live page; checked September 10, 2026 · First-party campaign support
SEIU-UHW’s own page supporting and sponsoring the proposal.
Where to look:
https://www.seiu-uhw.org/ca-billionaire-tax-act/
07California Billionaire Tax Wins Backing from 125,000 AFSCME Members
Yes on 40 · March 12, 2026 · Campaign-reported endorsement
The campaign’s report of the AFSCME California PEOPLE endorsement vote.
Where to look:
https://yeson40.com/california-billionaire-tax-afscme-endorsement/
08Billionaire Tax Act — Supporters Speak Out
SEIU-UHW · Undated; checked September 10, 2026 · Allied-organization support record
Publishes supportive statements from Robert Reich, Bernie Sanders, and Chris Murphy. These are SEIU-reported statements, not independent recordings verified here.
Where to look: Named supporter statements
https://www.seiu-uhw.org/billionaire-tax-act-supporter-content/
09California Billionaires: Wealth, Taxes, and Wealth Tax Revenue Estimates
Jasper Boll, Emmanuel Saez, and Gabriel Zucman · 2026 working paper; author-hosted version checked September 10, 2026 · Working paper
Working-paper estimate, not observed collections or an institutional NBER endorsement. Saez discloses unpaid design/scoring advice. The downloaded version has differing cover/abstract revision labels; no single revision date is asserted.
Where to look: Abstract and disclosure, PDF pp. 1–2.
https://eml.berkeley.edu/~saez/BSZ26CAbillionaires.pdf
10Correcting the Record: Addressing Some Legal Arguments About the 2026 Billionaire Tax Act
Brian Galle, David Gamage, and Darien Shanske · Revised January 9, 2026 · Proponent legal analysis
Galle, Gamage, and Shanske explain their defense of the proposal using existing court decisions. This is the drafters’ legal analysis, not a ruling on Prop 40.
Where to look:
https://eml.berkeley.edu/~saez/galle-gamage-shanskeCBTAlegal.pdf
11Proposition 40: official analysis
California Legislative Analyst’s Office · 2026 voter guide · Official fiscal analysis
Estimates tens of billions in new wealth-tax revenue over several years and possible income-tax losses of less than $1 billion a year. These periods differ: the figures are not a calculation of the lifetime net balance. The analysis also covers administration and interaction with Propositions 41 and 42.
Where to look: Fiscal Effects; Other Measures That May Prevent Proposition 40 From Taking Effect
https://voterguide.sos.ca.gov/propositions/40/analysis.htm
12The California Billionaire Tax: an expert report
Brian Galle, David Gamage, Emmanuel Saez, and Darien Shanske · Updated July 20, 2026 · Proponent expert report
The proposal’s drafters explain its funding estimates, payment installments, and qualifying deferral arrangements.
Where to look:
https://eml.berkeley.edu/~saez/galle-gamage-saez-shanskeCAbillionairetaxJuly26.pdf
13Professor Brian Galle on “How to Tax the Ultrarich”
Berkeley Law Voices Carry; host Gwyneth Shaw · February 17, 2026 · Interview with full transcript
A Berkeley Law interview with a full transcript about taxing the ultrarich. Galle distinguishes federal reform from the California proposal he helped draft.
Where to look:
https://www.law.berkeley.edu/podcast-episode/professor-brian-galle-how-to-tax-the-ultrarich-voices-carry/
14Expert Report on Valuation of Controlling Shares of Publicly Traded Companies Under the CBTA
Brian Galle, David Gamage, Emmanuel Saez, and Darien Shanske · February 5, 2026 · Proponent technical analysis
Explains publicly traded shares, private-company valuation rules, and certified appraisals.
Where to look:
https://eml.berkeley.edu/~saez/galle-gamage-saez-shanskeCBTAcontrollingshares.pdf
15California Could Lose Up to 217,000 Jobs if Congress Cuts Medicaid
UC Berkeley Labor Center · April 24, 2025 · Conditional economic analysis
An April 2025 scenario modeled $10–20 billion less annual federal Medi-Cal funding in 2026 and estimated 109,000–217,000 job losses across healthcare and other sectors. It predates the final federal law; those are not observed losses or a prediction of how many jobs Prop 40 would save.
Where to look:
https://laborcenter.berkeley.edu/california-could-lose-up-to-217000-jobs-if-congress-cuts-medicaid/
16Teamsters California Backs “California Billionaire Tax”
Yes on 40 · January 26, 2026 · Campaign-reported endorsement
Campaign announcement of Teamsters California’s endorsement, identifying 250,000 California members.
Where to look: Opening paragraph: endorsement announcement and membership.
https://yeson40.com/teamsters-california-backs-california-billionaire-tax/
17One of San Diego’s largest unions rolls out endorsement of billionaire tax
Yes on 40 · February 26, 2026 · Campaign-reported endorsement
Campaign announcement documenting UNITE HERE Local 30’s endorsement of the California Billionaire Tax.
Where to look: Headline, date, and opening paragraphs.
https://yeson40.com/one-of-san-diegos-largest-unions-rolls-out-endorsement-of-billionaire-tax/
18Oxfam America endorses the California Billionaire Tax Act
Oxfam America · April 13, 2026 · First-party endorsement announcement
Oxfam America’s published announcement explicitly endorses the California Billionaire Tax Act proposal.
Where to look: Explicit endorsement paragraph and publication date.
https://www.oxfamamerica.org/press/wealth-of-the-10-richest-california-billionaires-grew-by-nearly-50-in-the-last-year-making-them-the-equivalent-of-a-163-million-hourly-wage/
About this page. Published as a review draft by the Yes on 40 campaign, which advocates passage of the measure. Sources were checked on September 10, 2026. Research estimates, proposed legal provisions and endorsements are identified separately. This page is not individual tax or legal advice. Send corrections with the relevant source to the campaign’s press contact.
Vote Yes on Prop 40.
Vote Yes on Prop 40. Stand with the nurses, workers, community organizations and leaders backing a stronger response for California healthcare.