alt Hacker Newsbah! :( I don't understand how I'm supposed to call attention to the parts of my previous comments that were important to being understood, but disregarded in the reply if that is what was wholly inappropriate. Other than to not reply at all when previous comments are misunderstood or ignored.
Not replying is usually the strongest rhetorical move, for what it's worth. Long threads implicitly elevate the other side of the argument. If you're trying to dispositively conclude a debate, make your case once, dispassionately, and then don't restate anything you've already said.