I see it more as an explanation for why Donald Trump is tolerated and an observation of a style of tactic the right uses rather than an explanation for the Trump phenomenon. I have a few theories for why Trump was popular, which definitely aren't sufficient on their own but I think they're novel enough to be interesting.
On one hand, he kind of resembles a scummy lawyer. There's the line from Breaking Bad when they introduce Saul Goodman that I really like: "You don't need a criminal lawyer, you need a CRIMINAL lawyer". Basically, being a scumbag New York elite is actually a really useful property if they're working for you. This is a big component of his image as a "deal maker": he knows all of the Washington crooks personally and has made deals with them all of the time, so of course he's the one you want to send to Washington and not Crazy Bernie who gets played all the time.
This feeds into something else I think people really liked about him which is that he was willing to completely destroy the political elites. It was kind of shaping up to be a clash between two major American political dynasties until Trump came on stage and completely humiliated Jeb Bush. This, combined with his excellent showmanship (probably the only thing he's genuinely brilliant or even good at), reinforced the idea that he's "our" douchebag.
This feeds into some other psychological wizardry. Him saying unconscionably offensive things constantly reinforces the idea that he's a "truth teller". He incurs a high social cost by being awful, so maybe he believes in what he's saying enough that it outweighs those costs. Otherwise, why would he say them? I think a similar pattern occurs in abusive relationships: there's no way my partner is calling me ugly and stupid all the time to ingratiate themselves to me, so they must be telling me their true feelings and I can trust them.
Even having thought about this a lot there's still a pretty massive amount of cognitive dissonance when I try to understand why people like or even love Trump. It's extremely unnerving and I think that it's good to acknowledge that. I also think it's important to have a complex understanding of why the phenomenon exists so we can counter it, and I don't know if enough people are doing that right now.