What can I say? White supremacism is the default mode in American life. Always been that way, and it doesn't vary all that much. To point this out, doesn't make  one a bigot. It's doesn't even make one original. It's just not a very controversial thing to point out.

However, someone who acts like it's a big threatening deal to say that white supremacism exists, or describe what it looks like, is telling you, almost certainly, that he/she is self-consciously white. Because simply to say that white supremacism exists, as banal an observation as that is, IS A THREAT to it.