California Gov. Gavin Newsom, a Democrat who is considering a run for president as he approaches the end of his term, called for a national “billionaires’ tax” on Friday even as he fights another proposal targeting the wealthy in his home state.

Newsom also said the U.S. government should own a stake in artificial intelligence companies. His proposals, outlined in a Substack post, aligns him with the Democratic Party’s populist left, and he argued that urgent changes are needed to prevent the elite concentration of wealth and power from undermining democracy.

“It’s time for an economic reset for America,” Newsom wrote.

The governor announced his agenda a day after an influential health care union in California pledged to go forward with a ballot measure that would impose a one-time 5% tax on the assets of billionaires living in the state as of Jan. 1, 2026.