As a nonwhite person*, I pretty much have to consider racists as dicks. This is not to say that they can't be nice- as I have often said, nobody is unalloyed evil or good.
But racism is one of those things that, no matter how charming you are, no matter the contexts & circumstances under which you can be nice to fellow human beings, you're a dick. (Likewise, see Serial Killers.)
I'm a born southerner, myself. Lived in one part or another for 75%+ of my life. I know about southern hospitality and racism. Nice though some of those racists were to my face, they were dicks when I wasn't around. A concealed dick is still a dick.
* not that nonwhites can't be racists. They can be, don't let anyone tell you differently. My beloved paternal aunt is one...but she's a dick.
I see some circles of Venn that you seem to be talking about:
I might imagine that a person may not be a dick in all situations or to all people (aka racist). So a person who is genuinely nice to people of their own kind isn't a dick all the time. Once the race situation comes into play, bang, they enter dick mode.
Would we classify them as a dick then, even though it doesn't cover all situations? What if that person only enters racist mode 3 times in their life (because they live in an all-same town)?
Likewise, how we define racism may or may not include dick-ish behavior.
What if I think black people are better at sports than white people (Not my actual view). Is that racist?
If it is, how does that align with being a dick or exhibiting dickish behavior? So what if I think black people are better at sports? They might mean that I avoid playing basketball with Danny because I know he'll beat me badly every time so it's not fun.
That doesn't mean I've treated him badly, or said anything mean, or even hurt his feelings. It's not necessarily any different than Danny refusing to play WarHammer with me because he hates wargames in terms of how we treat each other or decline the invitation.
Anyway, I see shades of grey. Some people truly are dicks. Some people are dicks sometimes. Some people are racist in a bad way. Some people have racist ideas that don't grossly impact others.
In an ideal world, everybody would be nice, helpful, honest, courteous, respectful to everybody, and wouldn't have preconceived notions about any individual or group of people or treat anybody differently.