As he gears up for a possible presidential bid, California Gov. Gavin Newsom on Friday proposed a national “billionaires’ tax,” — a day after the state wealth tax measure he opposes qualified for the November ballot. 

Newsom’s counter proposal calls for a federal minimum tax rate on Americans worth more than $100 million, rather than a state level one-time 5% wealth tax that the governor argues could be dodged by billionaires who could leave the state for another.

Newsom, who said earlier this month that he is “considering running for president,” said the country should return to pre-2017 corporate tax rates and close offshore loopholes that allow multinationals to shift profits and pay less in taxes. He also said inheritance rules need to be rewritten.

“Over the next twenty years, this country will live through the largest intergenerational wealth transfer in human history, with roughly $124 trillion changing hands. If we do not act, that transfer of wealth among the ultra-wealthy will lock in a permanent American aristocracy of inherited wealth,” Newsom wrote in a Substack post announcing the proposal on Friday morning.

The announcement comes a day after California’s own billionaire tax qualified for the November ballot, having collected more than double the signatures needed. The measure, a one-time 5% tax on billionaire wealth introduced by healthcare workers union SEIU-UHW, in response to steep healthcare funding cuts resulting from President Donald Trump’s “Big Beautiful Bill,” has faced opposition from Newsom, California Democratic gubernatorial nominee Xavier Becerra and major lobbying organizations.

“We can’t let a single advocacy organization, however well-intentioned, write the state’s tax code on its own terms,” Newsom wrote, calling out the SEIU-UHW. 

The measure has also led to heavy spending from billionaires, who oppose the tax. The nonprofit, Building a Better California, which supports committees promoting two competing ballot initiatives that would nullify the billionaire tax initiative, if passed, has raised more $118 million — and $80 million of that comes from Google co-founder Sergey Brin.

Newsom says that he understands the “anxiety driving the wealth tax proposal in California,” but that he’s voting no on the California proposal, because he argues the measure dedicates almost all of the revenue to just state-funded healthcare services.

SEIU-UHW Vice President Debru Carthan said Thursday that the coalition supporting the tax would not back down.

“The billionaire tax will be on the November ballot,” said Carthan. “And we intend to win.”

About 250 billionaires would be taxed under the California measure, and the state’s nonpartisan Legislative Analyst’s Office says it’s likely that some billionaires would leave the state.

“You may not be able to pick up and move to Texas or Florida to shelter your income from taxation, but I promise you that billionaires can, and do,” Newsom writes. “Wealth is movable, and it shops for the state with the lowest taxes. The fight belongs at the federal level, where this broken system was created in the first place.”

Dan Schnur, a political science professor at UC Berkeley, called Newsom’s tax proposal “savvy political positioning” as it helps him enter the 2028 field without being seen as an opponent to taxing the rich.

“He’s not against taxing billionaires, he just has a different way of doing it,” Schnur said. “He now has an answer for progressive Democrats, whether in California or in early primary states, as to why he didn’t support the ballot measure.”

In Washington, another 2028 contender, California Democratic Rep. Ro Khanna, joined Vermont independent Sen. Bernie Sanders — both of whom supported the California’s initiative — in introducing legislation that would establish an annual 5% wealth tax on billionaires nationwide.

Newsom is also proposing a national public equity fund, giving Americans a stake in economic gains generated by artificial intelligence companies. The fund — aimed at workers left behind by automation — would support universal child care, free higher education, career training and healthcare. 

“Part of this fund could provide a real transition for the laid-off factory worker in Ohio or the 25-year-old coder in San Francisco who sent out a thousand resumes and got zero callbacks,” Newsom wrote. “This could include significant severance and portable benefits while we support them through the transition and into new jobs with programs like enhanced employment insurance.”

“As artificial intelligence reshapes the country, every American should own a piece of the future it builds,” Newsom wrote.

Other potential 2028 contenders are also beginning to stake out their positions on AI. Democratic Rep. Alexandria Ocasio-Cortez has introduced legislation proposing a nationwide moratorium on AI data center construction, which would create a temporary prohibition on the construction and expansion of data centers until Congress passes legislation to address the economic, environmental and safety impacts of artificial intelligence.

ABC News’ Will Lennon contributed to this report