If I recall correctly Trump recently visited Andrew Jackson sites in Tennessee. Those places generally have great presentations of history via placards, video, books, or knowledgeable presenters.
I imagine they were well aware of Jackson’s letter to Rev AJ Crawford in which Jackson suggests a future secession of states over slavery.
Trump might have heard all this very recently. It’s not his fault he knows more about Jackson than they do.
Is it his fault that they keep dismissing anything he says out of hand, and later finding out that they’ve just made asses of themselves again? Definitely, and it’s a pleasure to watch.