Trump presents a target-rich environment.
Here are a couple I just came up with, to be used repeatedly where appropriate, like Reagan’s “There you go again”:
“Didn’t your mother teach you any manners?”
“I’m sorry Donald, you don’t know what you are talking about.”
“On date A you said X, just now you said the opposite — were you lying then, or are you lying now? Or are you just making it up as you go along, and losing your memory?”
Please join in.