As I said back here, I think Jimmy Fallon's rating decline is not exactly, as some theorize, because he doesn't bash Donald Trump. It's in that ballpark but I think the problem is that Trump and his antics have made us all hyper-aware of politics and as I said, "Fallon's a nice enough guy but he doesn't seem as interested in what's happening right now as the other fellows."
And now, here's an interview with him in which he says, "I don't really even care that much about politics. I gotta be honest. I love pop culture more than I love politics. I'm just not that brain."