I can help narrow down the demographic leaving the DemRat party. It is too broad a statement to say that whites are leaving.
The whites remaining in the Rat party are the self-hating, racial mongering types who virtue signal their moral superiority. The whites who don’t have these “hideous virtues” are leaving in droves.
Whites who are easily racially manipulated by Demonrats today, would have been just as easily racially manipulated in past racist doctrines and schemes created by Dims. Their beliefs about human beings run skin deep.