Opposition to regulation and skepticism about climate change have become tenets of Republican orthodoxy, but they are embraced with extraordinary intensity this year because of the faltering economy, high fuel prices, the Tea Party passion for smaller government and an activist Republican base that insists on strict adherence to the party’s central agenda.

But while attacks on the E.P.A., climate-change science and environmental regulation more broadly are surefire applause lines with many Republican primary audiences, these views may prove a liability in the general election, pollsters and analysts say. The American people, by substantial majorities, are concerned about air and water pollution, and largely trust the E.P.A., national surveys say.

“Not only are these positions irresponsible, they’re politically problematic,” said David Jenkins of Republicans for Environmental Protection, a group that believes that conservation should be a core value of the party. “The whole idea that you have to bash the E.P.A. and run away from climate change to win a Republican primary has never been borne out. Where’s the evidence?”

But the leading Republican candidates are all linking environmental regulation to jobs and the economy, suggesting that the nation cannot afford measures that impose greater costs on businesses and consumers. Mrs. Bachmann drew loud applause 10 days ago at a rally in Iowa when she declared: “I guarantee you the E.P.A. will have doors locked and lights turned off, and they will only be about conservation. It will be a new day and a new sheriff in Washington, D.C.”

In an earlier debate she said the agency should be renamed the “job-killing organization of America.” She has called global-warming science a hoax.