Oh, how I miss the days of Johnny Carson. Johnny would make a joke about anyone, it didn’t matter their political stance. And, he kept his politics to himself. Colbert, Kimmel, et al can’t hold a candle to Johnny. (I used to like Letterman until he turned ugly and political during the Bush years.)
Letterman used to follow the Carson model by making jokes across the political spectrum. As he aged and started to chase people off his lawn the inner leftist came out.