The straw-person (traditionally known as the straw-man) fallacy consists in (1) misrepresenting someone's argument, (2) finding fault with the misrepresentation, and (3) concluding that the argument is defective. Karl Rove says that President Obama routinely commits the straw-person fallacy. I see it a lot among progressives, which suggests that progressives are not proficient at rational criticism. As for why this is, I don't know. If I had to guess, I would say it's because the academy is overwhelmingly progressive. If you never interact with conservatives, you're not likely to understand their beliefs, principles, values, or arguments.
Addendum: Note that the example of a straw-person fallacy at Fallacy Files is by a conservative, James Dobson. Wouldn't it be nice if the editors of the website used one of Barack Obama's fallacies, as described by Rove? How many of you think that is likely to happen? When I illustrate fallacies in my courses, I always use one by a progressive and one by a conservative. This shows the students two things: first, that I'm not biased; and second, that no political party or ideology has a monopoly on fallacious reasoning.
