Only Mitt Romney, the former Massachusetts governor, has a kind word for the E.P.A., and that is qualified by his opposition to proposed regulation of carbon dioxide and other gases that contribute to global warming.
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.
The White House disputes the accusation that it is burdening the economy with regulations. It says that it issued fewer new rules in its first two years than the George W. Bush administration issued in its final two years.
“This administration has shown a clear commitment to taking steps to protect our families from dangerous pollution, while at the same time ensuring those steps are implemented in a way that minimizes costs, maximizes flexibility and does not impede our economic recovery,” said Clark Stevens, a White House spokesman.
Mr. Perry has been at war with the E.P.A. almost since the day he took office as governor. He is leading a group of states in a lawsuit seeking to block the agency from putting in place rules limiting greenhouse gas emissions from power plants, refineries and other large sources.
On Monday, Mr. Perry called on Mr. Obama to halt all regulations because, Mr. Perry said, “his E.P.A. regulations are killing jobs all across America.”
In his book, “Fed Up, Our Fight to Save America from Washington,” Mr. Perry described global-warming science as “one contrived phony mess that is falling apart under its own weight” and a “secular carbon cult” led by false prophets like Al Gore.
Such regulatory and financial sentiments are shared by many Republicans in Congress and are encouraged by industries that are reliable financial supporters of Republican candidates — the petroleum industry, utilities, coal companies, heavy manufacturers and the U.S. Chamber of Commerce. Republican presidential candidates cross these interests at their peril.
“It remains to be seen of course, but my guess is that in order to get the nomination you’re going to have to be pretty solid on these issues,” said Myron Ebell, of the Competitive Enterprise Institute, a libertarian research and advocacy organization in Washington. “It’s going to be a litmus test or shorthand way for voters to see how the candidate thinks about not only big issues like global warming and energy rationing policies, but it’s indicative of other things as well.”
Mr. Ebell said that Mr. Romney, Mr. Gingrich and Mr. Huntsman, who have all said that global warming is real and at least tentatively attributed it to human actions, would suffer for it in the Republican primaries.
Mr. Perry’s anti-E.P.A. stance has been popular with Republicans in Texas and could carry him far in the primaries, said Ken Kramer, director of the Texas chapter of the Sierra Club. It may prove a liability in a general election, Mr. Kramer said.
“That kind of rhetoric is popular with a certain segment here,” he said. “But a lot of other Texans, especially those in major cities with air pollution problems, are not necessarily supportive of the governor’s war on the E.P.A.”
He added, “My sense is there’s definitely a difference between what plays well in Texas from a political standpoint and what plays well in other parts of country.”
Mr. Paul holds rather more complex views of the environment and regulation. He generally favors a hands-off approach to federal regulation, although he has backed some tax incentives for clean energy development.
He opposes tax breaks for oil and gas companies but supports Arctic drilling. He is skeptical about climate change but said in 2008 that there were unexplained anomalies in global temperatures.
Mr. Romney’s position may be the most complicated of all. In Massachusetts, he proposed plans to reduce greenhouse gas emissions and explored creation of a regional carbon cap-and-trade program. He has mostly backed away from those positions, but he says there is still an important place for regulation.
“I believe we should keep our air and our water clean,” Mr. Romney said at a town hall-style meeting in New Hampshire last month.
“Do I support the E.P.A.?” he said. “In much of its mission, yes; but in some of its mission, no.”
Despite a Supreme Court ruling to the contrary, Mr. Romney said the federal law did not give the agency authority to regulate carbon emissions. “I don’t think that was the intent of the original legislation,” he said, “and I don’t think carbon is a pollutant in the sense of harming our bodies.”