Not only that, but the US political system moving towards a much stronger anti-immigrant stance is literally reversing the brain drain and kicking out the best part of that deal, the smart people.
Eh, I dunno about the whole 'political system'. Maybe conservative populists, one of which just so happens to be president for now. After inauguration day in 2021, I expect he and everything he stood for will be discarded to the trash bin of history.
The US has had bouts of anti-immigration since it’s founding.