Trump hates all brown people.
They are either terrorists or mexicans
Trump especially hates mexicans.
They are bad hombres They bring drugs, they murder, they are Rapists. (although some, like his dishwasher and housekeeper) are good people
In his mind, all Mexicans must be illegals.
He doesn't know a lot of mexican people, but the ones he knows, ones he hired (dishwasher, house keeper) were all illegal, so it must be true.
He doesn't know Puerto Rico.
In his mind, they are brown people, speak mexican, and hence must also be mexicans.
He hates mexicans.
As such, the puerto rican mexicans are illegals.
He thinks to himself, "Why should we help the illegals."
They are rapists, and murderers.
They don't speak American.
He thinks they are poor, third world Country.
For Trump, Puerto Rico = Haiti.
Brown people living in destruction.
He looks at the devastation and thinks "this isn't so bad. Its third world country after all.
Again he asks, "Why should we help the illegals.".