Blacks and whites are both global minorities and have been for some time, being dwarfed by the number of Asians that exist. In the US "whites" are only becoming a minority because politicians have defied anthropology in declaring several Caucasian ethnicities as separate races for Census purposes. If one considered, as science does, that Arabs, Latinos, Persians, Jews, etc. ARE "white" then the demographics look a lot different. But US blacks are decidedly a numeric minority and haven't actually increased their numbers to any substantial degree since the last Census.