The simple fact of the matter is that during the 1950s and 60s, angry black Americans, especially those men who served in WW2, were just about fed up with foot-dragging on the Civil Rights front. And even though things were better outside the South, a lot of us had family there and we weren't going to put up with it. The threat of violent revolt in America's cities were a clear and present danger. So when black Americans negotiated Affirmative Action with Nixon, it was the kind of politics that nobody wanted to rehash.
In other words, America's most powerfully dangerous minority made it race and ethnicity because we said so. But it wasn't about race and ethnicity, it was about us and what we wanted. Because the NAACP is not about 'people of color' it's about black Americans. And we won. And we dictated the terms of how people talk about race and ethnicity in America. And it's going to continue to be that way until nobody (meaning black Americans) cares any longer, about halfway through the next black President's term.
Somewhere around the mid 80s, 'the Black Community' began to disintegrate as a singly focused political force. Black America itself became too large and diverse to sustain the myth of unified leadership. I would say the very end came with the deaths of the Congressional Black Caucus and of Ron Brown. But that doesn't change the fact that a new generation has tried to use the same tactics with 'multiculturalism' as blacks did with Black Power. Except, really who's going to burn down Detroit for 'diversity', the cast of Glee?
So basically we are living in the mediocre shadow of the political dynamic of a once unified black America that was so powerful that it redrew Congressional districts in every state. That power is gone, but some of the half-baked ideas and rhetoric about race and ethnicity remain. Some people worry about backlash, but just like with the actual end of Black Power, a significant enough number of black Americans really rose in competence and genuine social power, picking up the mantle of the best America we all want. And so (as we say) just like other ethnics, our struggles into the mainstream has strengthened and changed America for the better. But, you know... how the sausage was made ain't all MLK speeches, peaches and cream.
Don't expect that you can reinvent the blues or the Baptist Church or race relations just because it has been explained. We did that. It's done.