Ummm...if a white person feels guilty when racism is discussed, there's a good reason for that. It's because they know they harbor racist perceptions and feelings and don't want to be reminded.
There are long-ago slave owners on the paternal side of my family. My own grandparents openly expressed racist thoughts to us. Even my parents had racist reactions when my sister became pregnant by and planned to marry a black man from Southside Chicago she met at college.
But that's not ME. I have worked conscientiously to rid myself of the influence of racist white culture for decades. And I have accepted criticism--however painful--when unconscious racism (which is impossible to escape completely because it's endemic to the very cultural air we breathe) rose to the forefront.
So I know that when racism is discussed it is NOT an attack on ME. If one is not, in fact, a racist, then one should not be uncomfortable about discussing it.
Anyone who wishes to avoid discussions of racism does so because they don't want to have to face the racism they know they reproduce every day.
Nothing good has ever come from refusing to discuss painful issues. It's like the family who chastises (and in my case, disowns) the family member who raises the fact of historical childhood sexual abuse.
They are both the symptom and the FACT of family dysfunction.