Anderson Cooper's "47 percent" tax lie in the debate

In last night's debate, Anderson Cooper asked this question:

Congresswoman Bachmann, you said in the last debate that everyone should pay something. Does that mean that you would raise taxes on the 47 percent of Americans who currently don’t pay taxes?

Greg Sargent says:

I don’t really consider it part of my job here to think about where candidates messed up, especially since a lot of their factually incorrect statements are just playing to their audience, and you sort of have to expect a lot of that. But Anderson Cooper, the CNN moderator, has no excuse: his claim that 47% of American pay no taxes was inexcusable. Just terrible. The correct stat is that 47% of US households don’t pay federal income taxes, which is very different. It’s bad when politicians get basic factual stuff wrong; it’s terrible when CNN does. To me at least, the debate had a clear loser, and it was Anderson Cooper and CNN for that question.