All of the truly advanced nations, except Japan, are of white European origin. Black nations, without exception, from Africa to Haiti, fall at the dead bottom of civilization. In the United States, blacks also place last, and show few signs of independent progress. Hispanic nations hold the middle ground. This is not a recipe for harmony.
Racial tensions are fairly high today, and growing.
After fifty years of attempts to impose integration, American isn't integrated. If the minorities do not assimilate, as they gain power their assertiveness will probably increase. For blacks, none. They largely live in isolation in vast, utterly segregated, linguistically aberrant, self-sustaining ghettoes. Animosity smolders between them and everyone else.