I was curious about the exact question, so I grabbed the original survey from the Pew site - here's a screencap of the evolution bit:



As you can see, when it comes to the Buddhists, only 4% "completely disagree" - the other 15% only "mostly disagree", didn't know, or didn't answer. So the picture is a little better than it seems at first glance. Even in the most anti-evolution denominations, there's a substantial chunk of people who don't vehemently reject the idea; that's a lot of Americans who could be convinced by the evidence.