That doesn't affect the capital that either Space X or Tesla have to invest. It also doesn't affect whether or not Musk is still in charge of those companies.
Yep, what has the government ever done for anyone!
I don't imagine tax take would double, however many billionaires got fleeced, but the premise that the government would necessarily be worse at disbursing the funds than private individuals is laughable.
Nobody is talking about "leftist politicians."
I am suggesting something that might actually get the middle class, or those aspiring to join the middle class, to support and vote for the idea. I think it's pointless to talk about more radical concepts like a wealth tax or UBI without considering how such a thing could be made appealing to a majority of voters.
Taking ever more capital from the most effective/productive allocators and giving it to one of the least effective doesn't strike me as a good strategy.
A case like the Walton heirs is another story. I suspect we'd be better off taxing most of that wealth.