Puerto Rico is overwhelmingly white:
https://en.wikipedia.org/wiki/Demographics_of_Puerto_Rico
Literally for the vast majority of Puerto Ricans their DNA is derived from European ancestors. Only a tiny minority are related to African or Native American stock:
A recent study of Mitochondrial DNA (mtDNA) from 800 individuals found that patrilineal input, as indicated by the Y-chromosome, showed 66% of Puerto Ricans could trace their ancestry to male European ancestors, 18% could trace it to male African ancestors, and 16% could trace it to male Native American ancestors
Its vastly more white than Florida and vastly more white than Houston where Trump directly went himself in response to Hurricane Harvey.
I don't like Trump and I don't like how he's having a Twitter war with that mayor, but over 10,000 containers of aid have been sent and are currently sitting in 11 transportation ports around the island of Puerto Rico. The problem isn't that help wasn't sent, it's that distributing the aid after two historically devestating hurricanes is extremely challenging internally.
The big issue is the internal lack of truckers (only 20% of the planned trucking workforce that the Puerto Rico local planners prepared are available) and that the infrastructure for transportation has been heavily destroyed in many rural areas.
According to the governor of Puerto Rico:
"We need to do a lot more in order for us to get out of the emergency," Puerto Rico Gov. Ricardo Rosselló said in San Juan. "But the other thing that's also true is that the administration has answered and has complied with our petitions in an expedited manner."
http://www.cnn.com/2017/09/30/us/puerto-rico-hurricane-recovery/index.html
Edit: For anyone looking to donate to the relief efforts: