The current alt-right is a reaction against the glee with which the alt-left has greeted the notion that whites, and white males in particular, are the scum of the earth, and are being replaced by supposedly inherently morally superior "brown peoples". That can't happen soon enough for the alt-left, and they cheer on the "reconquista", etc.

Not surprisingly, they get pushback from the young men affected, who see no future for themselves in such a society.