Technique: Expose their ulterior motive. Everyone usually has one and even if they don't, make it look as though they do. And present it in the least flattering light possible, as though it was something that you uncovered against that person's wishes. Make that ulterior motive seem underhanded, self-serving and otherwise despicable. When presenting a persuasive argument to another person or group of people, the true motive behind the persuasion is often concealed. Why? Not because the true motive is necessarily invalid and immoral (even though it very well might be), but rather because there is always a more persuasive and acceptable, warm-fuzzy argument for the uninitiated. E.g. Bush says he is against National Health Care because of some populist principle of freedom of decision, when the real reason is because he is already protected by insurance and has no desire to help those who are not. He sees the initiative as a Robin-Hood-take-from-the-rich-and-give-to-the-poor atrocity fit only for some European Socialist society. Even so, he has the right to think that, but he should also have the balls to tell it like it is.