Because politics isn't about policy. It's about sounding tough and powerful, and like a leader. And that's what Trump is good at, even if he has nothing to back it up. And since people are dumb, they go along with it, because it's our stupid base animal instinct to.
See also, kids who get punched and called "retard" for reading books.
See also, kids who get punched and called "retard" for reading books.