"Turn-about is fair play."
"What's good for the goose is good for the gander."
"What goes around, comes around."
"The chickens come home to roost."
"If you can dish it out, you can take it."
Take your pick. Fact is, racism is not healthy for society, no matter who's doing it. But after subjecting African-Americans to officially-sanctioned racism from 1619 to 1964 (17 generations, or so) it should not be surprising to anyone if an African-American today thinks racism is a normal, integral part of life. That is, after all, precisely what they were taught by European-Americans for 17 generations: That your race is the single most important factor that determines who you are and how you will be treated...and this is an unchangeable and inescapable fact. A significant number of them still believe that - which is the inevitable result of that history.