They've been the faithful voters and foot soldiers in making things work for all groups in America, since they are diverse. Those who left LBJ's 'big tent' did so out of not wanting to share power with these various groups.
It wasn't just some trick by Reagan or Nixon. It had been their attitude all along that some should sit down and be told what to do by them. That they were doing them a favor by helping.
The Democratic Party took weaker positions and tried to ameliorate the wrongs piecemeal, because they know theruthlessness of the oligarchs. Just as the framers of the Constitution saw them upfront and far too close, knowing just how far they were willing to go to maintain control, eventually forcing a civil war to do the right thing.
And they have kept on pressuring all levels of an idealized society that has taken more from POC and the rest of the list for all these centuries. BLM and all these movements are necessary to bring this nation closer to where it needs to be, where it'd be on its best day.