Groups that have had (or have had the promise of) something react differently when that something is taken away, compared to groups that never had (or were promised) it in the first place.
There were never the same promises made to black men as were made to white men. So while black men have lost that nebulous "american dream", they're much less interested in demagoguery and strongman solutions.
A portion of white men, however, might feel a sense of strong injustice at losing something that has felt almost like our birthright. Others might change their perspective and realize that the promise was never all that concrete to begin with.
The existence of the Black Panther Party and numerous similar movements for decades, says otherwise. Louis Farrakhan is an obvious recent example of a demagogue.