I've seen this point before, but it's not an argument for keeping rates low. "If we raise rates, the rich will just find ways to avoid them!" People find new ways to try to murder and steal all the time; that doesn't mean we throw up our hands and make it legal to do so.
The solution is to raise rates and fix loopholes, difficult a political lift as that may be.
The solution is to raise rates and fix loopholes, difficult a political lift as that may be.