There will be a point of "critical mass" where he has negligible "strong supporters" and a majority of "strong disapprovers" among the white middle class. At that point, people will feel free to openly criticize and mock him without any blow-back from strong supporters.
Once that point is reached, it's all downhill.
But, at some point, people are going to come right out and start saying what they think of the poor, of the blacks, of the Muslims, of the homosexuals, of the feminists, of the corrupt politicians, or the activist judges, and of the petty criminals. That's torches and pitchfork time.
I think that this will snowball. Many people live lives of quiet desperation, thinking "unacceptable thoughts" without realizing that all the people around them are actually thinking the same thing. If people start being honest, a lot of eyes will open and the outrage will increase very quickly. There will be a Rising.