Well, we banned the bigots and deleted the comments. It's not perfect, but it's what we got.
This specific problem is more of a personality issue, I used to see it a lot working retail. Some folks respond to criticism or anything they perceive as "getting told what to do" by trying to get the last word and exert some power over you. In the workplace, this was usually customers who couldn't use a coupon/ran into a rule we simply couldn't bend for them, and demanded something, *anything* to feel in control of the situation. "Get me your manager to tell me the same thing", or when I am the manager "Well give me a comment card to fill out", that sort of thing.
It's a similar thing on here; some folks who receive a warning or have a post taken down for any reason will simply refuse to move on, and keep escalating things in an effort to assuage their ego. I've had multiple people demand I delete their accounts after I take down some naked picture, usually while invoking Spike's name to "go over my head".