I'm pretty sure African-Americans are aware of their mixed ancestry unlike those whose entire claim to superiority is based on the purity of their "blood" and genetics. Trump glorified the neo-Nazis in Charlottesville by stating in Arizona that those who support the removal of Confederate statues were "trying to take away our culture, trying to take away our history." It's Trump's use of the possessive adjective "our" that links him and his followers to neo-Nazis hate groups. 
Those supporting the Confederacy were disloyal to their country--more attached to their backward and undemocratic way of life than they were to American values of fairness and decency.  The majority of white people do not support Trump and his approval ratings continue to plummet. Those who support white supremacy are a minority, actually a minority of a minority. They can never win so they engage in histrionics. Their cause is as lost as it is pathetic.