The best way to bring Levin back down to earth is to not listen to his program. His audience isn’t so large that he can afford to lose people. Additionally, I doubt there is a huge anti-Trump group of #nevertrumpers out there who will fill in the slot when you stop listening.
Levin will be forced to decide. Maybe he’ll get sane again.
While he does have the airways, willfully changing his stance purely on pocketbook listenership makes him a big fat fake. I once was a listener as well. No mas. No mas.