In his blog post How CEOs Can Improve Speeches, Nick Morgan analyzes the opening pargraphs of Obama's state of the union address:
You can tell when rhetoric is empty — and therefore should be cut — because it would never be possible to say the alternative. Could a president begin by insulting the Speaker, 'dissing' a tragically ailing representative, trashing the democratic process, or coming out against jobs? Of course not. Therefore, nothing is being said. Speeches are much more interesting for the audience when they dispense with the polite nothings and get right to the meat.
In other words, could someone substantively disagree with your point? If not, it's probably not a very interesting point.
Once you know a counterpoint exists, understand the logic of the counterpoint — this will help you affirmatively explain your point with clarity and rigor. As I noted in a post a couple years ago, an efficient and reliable way to probe the depths of a person's knowledge of an issue is to ask the person to explain the other side's perspective.