Metaphorically, one might say that what Trump is "putting on" his supporters is a mirror. "I'm one of the guys" is the constant meta-and sometimes explicit-message. This facilitates two things. It prevents Trumpsters from feeling threatened which, in turn, enables their basic identification with him. Adding some substance (and I use the term loosely here), the Donald has unequivocally and repeatedly declared that he is pissed off, providing more tangible material with which his furious followers can identify. From a logician's point of view, the argument is, "You are strong. You are one of us. Therefore we are strong". Or, symbolically, "A=B. A=C. Therefore B=C".
All would agree that a fifty-something who's long been out of work, and has exhausted the limited vocational benefits of a high school diploma, is likely to be highly frustrated and quite angry. But, showing anger is generally socially proscribed. [Many psychologists have decried "venting" anger since he late 1970s when it was shown to be self-reinforcing. Indeed, the psychotherapy highway is littered with the casualties of earlier days. Primal Scream Therapy, of John Lennon-fame, is the most absurd example.] Instead, it grows internally because-as is the case with ire-the related thoughts are repeated so often. And it is the intensity of this anger that enhances Trumpsters' identification the most, supporting their wish to share his power to solve their problems. The hopefulness that this wish produces, even if unconscious, acts as a reward that reinforces the identification.
In summary, Trump projects power as a rule. This projection is being amplified by his symbiosis with his political supporters. As a group, Trumpsters desperately want relief both from their plights and the consequent rage. Their reinforced identification with the Donald supports the unconscious desire to partake of his power, bringing respite into view.
On a conscious level, Trump's supporters see him as an honest change agent, hardly enough to warrant forgiveness for his vaunted venomous verbage. Nor can they easily explain their exoneration of him. That is, of course, because the answer lies inaccessibly wedged deep in the unconscious. It is the place that this identification calls home. From another perspective, the presence of identification means-by definition-that Trumpsters' criticism of the Donald would also be self reflexive. That makes refraining from such critique a method of protecting oneself from the related pain, albeit unconscious.
So, they support him despite his unreserved contemptuousness because they are moved by profound and powerfully conditioned identification; and because they are utterly oblivious to it.
What I mean, of course, is that he typically speaks in an unvarnished and fairly forward fashion. But the Donald has, of late, subtlely widened the scope of his presentation. His topics are far more frequently fodder for the working class now, and occasionally even prurient (see Musings on 3/4: Applied Clinton-Speak). Further, his delivery has become considerably more intense and forceful, just over the last year. (And I've been watching Trump since the 1980s.)