The All-American Basketball Alliance has caused tremendous offense in the United States, by proclaiming it is only accepting men born in America to Caucasian parents.
Just because the NBA is stocked with black men, holding a white minority, doesn't mean such an extraordinarily offensive step is necessary.
Basketball is a poor man's sport that does not require expensive training. Thus, it appeals to many financially poor minorities, who love said sport and see it as a path to a wealthy career.
Story Source: Whites-only basketball league targets Augusta, Georgia