my personal thought on this matter is that it is unfair to Hitler's *victims* to use this comparison lightly. Likening another to him, or even invoking his name in this manner, breeds the lightness and familiarity of such frequent and common exposure. If one is to point out a fallacy--do it directly. Why spice it up? The fact that talk show hosts would converse in this manner should demonstrate why it is uncivil.

Secondly, bringing Hitler into civilized debate is a fallacy in itself. Unless one is using this method in a close parallel that warrants it--i.e. a political leader whose policies lead to a large number of deaths, who uses blatant propaganda, who heads a fascist regime, etc. etc.--than it is being used as a faulty emotional appeal, meaning that it is designed to evoke strong emotions in the listeners/readers that aren't really about the topic at hand. Not only is it fallacious, but it shows a lack of reason and skill in the one who invokes it.