I don't agree with this at all. I do not feel there is any factual basis for this statement.
Then you've never listened to Limbaugh, Hannity, and others. I agree with them most of the time, but on scientific issues they're ignorant. Rush in particular admits as much.
That the 15 years of science bashing on the environmental front have now spread to bashing all of science, and evolution in particular is obvious, right here on these threads.
Much of the blame is not on Limbaugh and conservatives. They're just ignorant of the facts. The real blame is on the few prostitute "scientists" owned by the environmentalists that have been in the media since 1970. They've given science a black eye, and the scientifically illiterate creationists have merely taken advantage of it.