The Megyn Kelly incident is a typical example of a kind of wypipo racism, which at its best is an extreme form of ignorance (though that Kelly is a big racist has long been established so I am not let her off the hook here). You know, "I haven't really thought much about this blackface thing but I heard blackface was bad but it doesn't make any sense to me because blackface seems, like, ok?"
My point being that if there's some notion that something is racist, if you (as Kelly obviously does) have some notion that black people generally think something is racist, maybe your default position should be... this is probably racist? What I mean is that you don't have to spend any time obtaining a sophisticated understanding of the history of blackface in America to think that maybe you should just... listen to black people a bit. Maybe you don't know why blackface is bad, but it isn't as if "do not dress in blackface" is some major assault on your individual freedom, unless you get weepy every year when people say mean things about the inevitable racist Halloween frat parties. It's pretty easy to just accept "ok this thing I don't understand and don't want to bother understanding is probably racist" and move on.
Unless, of course, the thing that pisses you off is that black people (in your mind) are telling you what to do. And that trumps (so to speak) everything.