They'd be able to move their capital outside the country while still residing inside it, and enjoying the other U.S. benefits. Assuming those with the ability

They'd be able to move their capital outside the country while still residing inside it, and enjoying the other U.S. benefits. Assuming those with the ability to move their wealth overseas would do so, the people most affected by substantially raising taxes would be those without enough wealth to move it... those outside the top 1%, 0.1%.. whatever super-rich people the policy aims to target. Although it isn't ideal that the wealthy can 'shop around' for the most tax-friendly nations, it certainly happens, and Switzerland is a fine example of that capital flight in effect.