There are two ways in which people can conceive of themselves as minorities. They can think of themselves as minorities in terms of their power or status or as minorities in terms of their numbers. African American members of the middle class may think of themselves as minorities in both ways, or in only one.
African Americans in the middle class can think of themselves as having less power or status, though this is getting harder. There is still a fair amount of prejudice against African Americans. They often do not hold positions of much power, particularly compared to white people. They can certainly think of themselves as being a lower-status group.
It is quite easy for middle class African Americans to think of themselves as a numerical minority. They can do this in two ways. First, they can see themselves as a minority within the US as a whole. African Americans only make up about 10% of the population. Therefore they are automatically a minority. In addition, middle class African Americans can see themselves as a minority within their own race. They can feel that most African Americans are poorer and can feel that they, themselves, do not fit in with their own race.
African Americans in the middle class can see themselves as minorities in any or all of these three ways.