Blacks who experienced Jim Crow firsthand are getting older and no longer wield the political influence they once had. Younger black generations don't have personal experience with that. I've read that younger blacks do not feel as closely tied to the Democrat party as their elders and an increasing number are registering as Independents.
Also there is a growing black middle and upper class and they will vote their pocketbooks.
It will also be interesting to see what happens politically when blacks are definitely not the largest minority group nationwide as Hispanics will pass them. When Democrats start rampant pandering to Hispanics (which has already begun) and take the black vote for granted, that may ruffle feathers.
I'm just about finished with Judge Clarance Thomas' book. Here's a man - an intelligent man - who came out of the south at the end of the Jim Crow era who slowly realized that it was the Dems doing harm to blacks and not Pubs. It's right there where anyone can see it. The information is right there for anyone to know it. And yet - blacks as a block - will continue to pull the lever for the Dems. Please, someone tell me why!