I kinda think that black Americans with jobs are aware that illegal immigrants take jobs away from them, especially the minimum wage ones. Publicly they maintain political solidarity with the Democrat coalition (but not this time!!!) but friction between blacks and Hispanics goes back decades and is not going away.
As for PR, they should seek annexation with Cuba, IMO. The PR’s I knew in the military admired Cuban food & culture, and thought Fidel Castro was mistreated by the `evil yanquis’.
Puerto Ricans hate Cubans.