Joined: Oct. 2005
[Graffiti moved to Bathroom Wall. - Wesley R. Elsberry]
I believe he's getting it from a Gallup poll from 1991. Cited on a site which apparently is trying to foster religious tolereance... it's also the very first link that comes up when you google "polls evolution"... pretty lazy.
Relgious Tolerance - Evolution Polling page
A more recent poll shows the number at 15% from CBS News...
CBS Evolution Poll
However... in both polls there is a large percentage of people that believe in evolution of some form... it's really pretty depressing how deluded most Americans are.