I have to say that I have seen a shift in real life. Black people I know who are lifelong Democratic Party members asking out loud how the party has reached this point.
And for some of them President Biden wasn't really a top choice in the first place. I heard that going back to the last election. But now, the talk is a little different. A little more pocket book politics really.
But the only time I hear any pro, or at least not anti, Trump stuff is the younger folks. There is some shift in opinion on the ground.
How big, I dunno. Mostly I know older people. Where I live the Democrats have always trended a little more conservative than the national party.
Something that I have heard for years is that the Democratic Party takes votes of Black people for granted. And no matter who you are it doesn't feel good to go unrepresented in practical effect.