Yeah about that, how is THAT not against that constitutional right to not have movement between states restricted that was brought up before?
It's probably unconstitutional on its face, but it can't be challenged in the courts unless it actually passes into law -- right now, it's just a proposal.
There is a (very thin) argument that because wealth accumulates over time, California is in fact taxing wealth that was made in California, even though the taxpayer is no longer a California resident. While thin, this is not a completely bullshit argument; the basic principle that "income is taxed where it is made" is a well accepted principle, which is why a resident of State X who works in State Y has to pay State Y income tax on the income even though they don't live there.
This principle has been recently stretched by certain states trying to claim that "A resident of State X who *normally* works in State Y has to pay State Y income tax even when working from home in State X, because they *would have* made that income in State Y were it not for the pandemic." That is a HUGE stretch and likely unconstitutional, but the legal challenge to it has only started working through the system.
It probably does. This is a brand new law with lawsuits trying to get it tossed currently happening.
It's not a brand new law, it's only a legislative proposal which hasn't even been voted on.