I rarely listen to Levin but I did hear him the other week on an anti-Trump rant. Perhaps I was unfair to him.
Conservatives can back whomever they want, but I object to their habit of labeling anyone who doesn't support more and more foreign interventions as somehow not conservative. Likewise, I do not think support for free trade and trade treaties that erode our sovereignty is a conservative position.
The ivory tower conservatives I have most disdain for are the neo-cons like William Kristol who have got every major policy issue wrong, yet now want to run a third party candidate to block Trump and hence elect Clinton.
Levin has indicated that he would like to ask Trump how he would deal with the trade imbalances without imposing tariffs that would be like Smoot-Hawley, and the effects many believe it had during the Great Depression. I believe he is in agreement with Trump regarding immigration and the wall.
Trump had come on to the show early on, and the discussions were very amiable, and Levin indicated that he liked him a lot, but later when Trump started name calling his opponents, he stopped coming on the show, though still welcome. Levin has defended Trump from attacks against him that were unfair, and still does, though he is growing increasingly frustrated over the name calling, and most recently, Trump being unwilling to debate Cruz one on one.
Mark believes, and I agree with him on this, that if Trump alienates too many of the conservative bass, Hillary will win, will name 3 or 4 Supremes during her 4 or 8 years, and if she gets the house and senate as well, it will be the end of the country as we know it. I'd prefer to see Trump and Cruz join forces, if that is still possible.
If you listen to Levin, you'll find he rants a lot. My wife and I find it very entertaining because they are aimed at establishment members of both right and left equally. That said, I find Trump entertaining, too...he has really pulled back the curtain on the establishment right, and shown us how little our vote means to them after they've lied to us to get elected.
Levin has labeled a few of the conservatives that you listed as phony conservatives as well, along with many, many in the republican establishment. His radio show is free, and his archived shows are always available free at his web site...if your curious. Mark was chief of staff for Edward Meese in the Reagan admin, so has ample real life experience in the game, unlike other talk show hosts.