Mark Levin would be wise to have a long talk with the folks at the Mises Institute (mises.org) like Tom Woods, Lew Rockwell and Peter Klein. They would be able to advise him on a way to structure taxes that would respect liberty and be economically beneficial.
JWK
If Mark Levin can succeed in drawing interest to a Constitutional Convention, and that interest actually bears fruit, then this is the sort of question that can be raised during same.
Mark Levin is at the very least, putting forth solutions, along with a way to discuss those solutions. Nothing he presents should be considered written in stone. But, we must start somewhere. And Mr. Levin is leading the way.