I hate to sound like I’m defending Newsom because I think he’s a snake who only wants more power for himself, but implementing a billionaire tax at the federal level is legitimately the best way to do that kind of thing.

It’s too easy for anyone, especially obscenely rich people, to claim residency in another state. It’s much more difficult to shift your tax burden to another country. CA would absolutely lose some amount of tax revenue if they were the only state in the country with this kind of tax. No, all the billionaires wouldn’t leave, but they will certainly find the loopholes.