He should say "I've instructed my departments to compile a list of every communist, trans person, Palestinian, BLM activist, and I'm going to leave that list on my desk January 19th regardless of who's term starts the following day. Which president do you prefer has that list?" you know Blue MAGA would be ecstatic if he did that.
This comes on way too strong and would backfire. Their electoral strategy is already blackmail anyway, and it works on a lot of left liberals.