A 2005 Harris poll reported that 73 percent of Republicans believed in creationism as opposed to 58 percent of Democrats and 57 percent of independents. (The numbers are higher across the board likely because of phrasing that, again, seemed to equate creationism with belief in God.) This poll also found that people in the northeast and west were much less likely to believe in creationism than those in the south and midwest, and that people over age 55 were much more likely to believe than those under. A 1991 Gallup survey found that college graduates were less than half as likely to believe in creationism as those lacking a high school diploma. Likewise, those with an income greater than $50,000 per year were half as likely to be creationists as those with an income under $20,000. In 1997 Gallup reported that 5 percent of scientists believed in creationism, which depending on how you look at it is either alarming or a relief.
How does the U.S. compare with other countries in terms of belief in evolution? Not so hot. A study of attitudes in 34 countries published in Science in 2006 shows that the United States ranks last in popular acceptance of evolution except for Turkey. Almost 40 percent of Americans in this study flatly rejected evolution, whereas the comparable numbers in European countries and Japan ranged from 7 to 15 percent. That may partly reflect U.S. high school kids' dismal math and science scores relative to other developed countries, which to my mind underscores a home truth: the more you know, the less you take on faith.
From: The Straight Dope-Fighting Ignorance Since 1973 (It's taking longer than we thought)