His idea of the American dream is white supremacy.
As in the 1860s and the 1960s, were at another historic inflection point where things have to change.
Donnie represents the white supremacists' last best hope to keep the social order where non-whites are constantly kicked and whites are constantly protected.
*that* is what they think if as the American dream. All this talk about the land of opportunity, making things better for your kids than it was for your parents, they don't want that for non-white people. That's not their idea of the American dream.
Democrats represent a new era. I won't pretend we'll be able to eliminate bigotry, but we'll make some major improvements for minorities, and that will represent the death of the American dream for those white supremacists, just as the 13th amendment represented the end of the "southern way of life" for confederates.
They shouldn't fret. If history is any lesson, they'll just move on to find new ways to hate.