One or two, nothing close to all. It's always an empty threat since time immemorial. Here's a 1936 FDR speech mocking it:

"A number of my friends who belong in the very high upper brackets have suggested to me on several occasions of late, that if I am reelected president, they will have to move to some other nation because of high taxes here. Now, I will miss them very much..." (audience breaks into laughter)

It's a manipulative tactic by greedy assholes to cow foolish people into accepting their demands of tax evasion to burden ordinary people.