According to the Laffer curve it should probably be 70% or so to maximize government income, but yes.
If you tax them 100% they'll just stop working or bail to another country, and then you collect zero tax revenue from them. At 70% most of them will just suck it up and pay.
(I realize France is a counterpoint here, but I'd argue it was a half-assed attempt, and they have neighboring French-speaking tax havens that have no real U.S. equivalent.)