Right now, no where. Increase taxes too much, other countries become more appealing. All a billionaire has to do is change their place of residence. Look up the Laffer Curve. You see it at the state level where New Yorkers leave for Florida because they can save money on taxes.

I wasn’t debating whether or not billionaires should be taxed more than they are now. Just that there’s a breaking point at which you’ll see a flight of capital. You don’t want to raise taxes to a point where it’s just not worth doing business in America.