Quoting a post I made earlier on the Flame board:

Depending on question wording, polls show about 20% to 40% of the public do not think that evolution should be taught in public schools at all. A solid majority think that creationism should be taught in some form. Only around 30% of the public are in favor of evolution only.

http://people-press.org/commentary/display.php3?AnalysisID=118

Among self-identified conservatives in the most recent Pew poll, 51% favored teaching ONLY creationism in public schools. That rose to 67% among evangelical Christians for creationism ONLY.

http://people-press.org/reports/tables/254.pdf

Pew is one of the more respected survey outfits, btw, they are hardly a bunch of liberal hacks.