Yes, and some probably Yes.
The problem with the "racism" label, like the "homophobe" or other labels is that it makes it very awkward to call out stupid or evil people in polite company of they happen to be black, Jewish, or muslims etc. (or annoying gay people with the other label).
So I don't get my panties in a twist when I see anons spouting racist bullshit. Like you say they could be shills, or they could just have a point.
It's when anyone resorts to unjustified violence (and gross generalizations) that we need to draw the line.