That's what I am seeing also. Up until John F Kennedy ran for president the vast majority of blacks were Republican. Kennedy made a deal with Martin Luther King to get him to switch parties so that JFK would get the black vote. MLK switched parties but the black migration from Republican to Democrat didn't really happen until Lyndon Johnson's Great Society (aka welfare) plan. Johnson decided rather than fighting against blacks he would use them. Welfare was created, not to help the poor, but to buy votes. And the poor, looking for "free" money jumped on that band wagon. Poor women realized they could get more money by having more children and that if they had a husband then they would get less or no money. And that set up the destruction of the black families in America. And with broken marriages comes all of the problems associated with it. And the Dems just kept playing on that because the could buy more votes.
Now we are at a point where America is the least racist we have ever been but the left keeps preaching that we at the worst we have ever been. If they don't keep as many people believing that then they are over as a party. People will leave them in droves.
I think there is a fairly sizable exodus going on in the past 10 or 15 years of blacks returning to the anti-slavery party their predecessors used to belong to. But that is just my opinion and I could be wrong.