Mark Ruffalo is taking another swing at Gavin Newsom, accusing the California governor of protecting billionaires while positioning himself for a possible White House run.
The Marvel star ripped into Newsom over his support for a ballot measure that could derail a proposed tax on California’s wealthiest residents, reopening a feud that erupted over a major Hollywood merger just weeks earlier.
“Once again. Just like the Paramount merger, Gavin Newsom does what he always does: Sells out the working class people for the billionaires again and again,” Ruffalo wrote Wednesday on X.
The actor also accused Newsom of backing legislation that would make it impossible to tax the wealthy, a charge that comes as Californians prepare to vote on two competing tax proposals in November.
It’s beyond sad. It’s beyond disappointing; at this point, it’s disqualifying for anyone with ambitions for higher office as a Democrat, or a Republican, for that matter, to be fighting to keep billionaires from being taxed while kids don’t have health insurance and the cost of… https://t.co/dDLnTRohgv
— Mark Ruffalo (@MarkRuffalo) October 16, 2026
Proposition 40 would impose a one-time 5% tax on the net worth of billionaires who lived in California on January 1, 2026. The payment would be due in 2027, although taxpayers could spread it over five years at an additional cost.
The measure generally exempts real estate, pensions and retirement accounts. It has the backing of the California Democratic Party and the Service Employees International Union-United Healthcare Workers West.
Newsom opposes the billionaire tax and has endorsed Proposition 42, which would prevent California from imposing new state taxes on ownership of personal property, including financial assets. It would also restrict retroactive taxes, potentially blocking Proposition 40 even if voters approve it.
The governor has argued that taxing wealth at the state level could drive rich residents out of California. He’s instead supported a national approach, including a minimum tax on people worth more than $100 million.
“I am proud to stand with firefighters, blue-collar unions, veterans, seniors, and small businesses in support of Prop 42,” Newsom said in a statement released by the measure’s campaign.
Once again. Just like the Paramount Merger Gavin Newsom does what he always does. Sells out the working class people for the billionaires again and again. Not only that but endorses a bill that will make it impossible to tax the wealthy at all.https://t.co/YCLE9ZrYnJ
— Mark Ruffalo (@MarkRuffalo) October 14, 2026
“We all agree that Californians deserve to have their retirement and life savings protected from new state taxes so those savings are there when they need them.”
Google co-founder Sergey Brin is among the wealthy Californians backing Proposition 42, which would also limit the state’s ability to impose similar taxes in the future.
Ruffalo has little patience for Newsom’s position, particularly with the term-limited governor attracting attention as a potential Democratic presidential contender in 2028.
“It’s beyond sad,” the Oscar-nominated actor wrote Friday. “It’s beyond disappointing; at this point, it’s disqualifying for anyone with ambitions for higher office as a Democrat, or a Republican, for that matter, to be fighting to keep billionaires from being taxed while kids don’t have health insurance and the cost of living goes sky-high.”
Ruffalo also accused the governor of putting corporate interests ahead of everyday Californians and urged him to reverse course.
“The people need a champion, man. A real, bona fide champion who isn’t just tough in tweets or press conferences, but tough when it comes to the real imbalances people are struggling with every day: billionaires vs. people and the planet.”
The actor even took a swipe at Newsom’s public exchanges with President Donald Trump.
“Gavin, we aren’t looking for the Democratic version of Trump. That was a good goof. Please try something else. It’s tired,” Ruffalo wrote.
Rep. Ro Khanna, a California Democrat supporting Proposition 40, has also challenged Newsom over the competing measures.
Khanna accused the governor of catering to wealthy political donors and criticized his endorsement of Proposition 42. “You can’t be anti-Trump and then do the bidding of Trump donors,” the congressman argued.
Newsom’s dispute with Ruffalo stretches beyond California’s tax policies and into one of Hollywood’s biggest recent business deals.
The actor had opposed the Paramount-Warner Bros. Discovery merger involving David Ellison’s Skydance, pressing California officials not to approve a settlement in an antitrust case brought by a coalition of state attorneys general.
After the settlement was announced in September, Ruffalo accused Newsom of handing a victory to Trump and his wealthy allies. He called the merger a “bad deal for this country” following a federal judge’s approval on September 30.
The transaction was completed in October, leaving the two men at odds over a deal that reshaped the entertainment business.
Ruffalo’s opposition also attracted accusations of antisemitism from some critics, while other Hollywood figures defended him. Despite the controversy, he is expected to return to the newly Skydance-owned HBO for a second season of his crime drama “Task” in 2027.
A Hollywood political operative told Deadline that Ruffalo’s involvement in the merger fight had increased his influence among Democratic activists opposed to the Ellisons.
The actor also criticized Newsom’s veto of an artificial intelligence safety bill earlier in October, calling the decision “a mistake” and urging people to “follow the money.”
Newsom has not formally announced a presidential campaign and has said he will decide whether to run after the midterm elections.
Ruffalo, meanwhile, wants the governor to reconsider his latest tax position.
“Let’s hope Gavin gets some sense and walks this back,” the actor wrote. “It’s crazy that this is what he chooses to spend his political capital, and part of his legacy, doing.”