And it isn't true. While they don't cite their poll, there's really only one they can be talking about, the National Geographic-Roper Geographic Literacy Poll, which was run in 2002 and again in 2006. In 2002, 89% of Americans could locate the US on a map. in 2006, 94% of Americans could locate the US on a map.
Blowing this question is like having trouble answering this one while on national television: "Recent polls have shown that the sky is green. Why do you think this is?"
Sky. Not. Green.
Come on. We may be stupid, but we're not that stupid. Altho the person writing the question is that stupid, if they think that 89% or 94% is somehow like 80%, or if they think the viewing audience isn't going to notice and complain.
FWIW, I found that poll on my own, altho other bloggers found it before me: