You are giving Americans, specifically Trump supporters, way too much credit if you think they would even consider the facts of the situation. To them Puerto Rico is another country (again forget the facts) full of Mexicans and while it is sad that they are dying and shit we got real problems to focus on here in the homeland (namely dumb white people) so its ok to fuck him. He just says what the rest of us are thinking....75% of Puerto Rico was white in the 2010 census.
Trump doesn't care about you unless you're rich, related to him, or he thinks he can trick your dumb ass in to being a pawn for him. Since the majority of PR doesn't meet any of those, he's quite happy to throw them under the bus.
Even worse than Trump is that millions of Americans support all the evil shit he does and says. Trump won't be there forever but these assholes are not going anywhere.