Joe, infighting is what you get in real fighting. Unfortunately, that's not the stylized ritual of boxing and Greco-Roman wrestling. In real fighting, one or all combatants end up very injured or dead and it's over very quickly. There's no referee to enforce any rules because there aren't any. I know; I taught it.

Intelligent discussion, on the other hand, has rules. When those rules are repeatedly broken the discussion (such as it is) is and should be terminated.