Banning people is only a temporary measure. I seriously doubt it would "fix" the problem. I think we all know from past experience, if you ban someone who really wants to be here, they'll come back under a different user name. It's happened before, it will happen again.
The trick is in convincing the people to whom you're referring, to change their attitudes. And that is never easy. All we can do for now, is hope for the best, and try to catch the really nasty posts before it goes too far. Maybe, after they've had some of their messages deleted, they'll get the message that they need to tone it down.
Or, maybe the admin will get tired of it all and ban those people. I don't know. All I can think of, are the words of the late Rodney King, "Can't we all just get along?"