His flexible quickness of wit was incredibly impressive in the ‘80s and early-‘90s.

But, he’s become brittle. You can see it in his interviews and conversations now, where he often makes interlocutors repeat something before understanding it and responding to it, even though it was said clearly.

I suspect he’s lost a few steps and is running mostly on muscle-memory these days. He has lost the flexibility of thinking to make truly insightful jokes; he relies instead of stereotypes and is irritated that those stereotypes are increasingly being rejected by the left.