"Some of our opposition on the Hill just comes from ignorance about what EPA's authority actually is, and its obligations under the Clean Air Act," Willcox said. "We're looking for an administrator who will embrace that, and get us the reduction in carbon pollution that we need."
That's a worrisome possibility for business groups, who say the EPA has no such authority.
"They've definitely taken their regulatory authority to places that were not necessarily contemplated by the laws when they were written -- greenhouse gases is an excellent example of that. ... And we have a problem with that," said Ross Eisenberg, the vice president of energy and resources policy for the National Association of Manufacturers.
He said the problem had grown worse in recent years as the Obama administration had tried to flex its regulatory muscles more instead of dealing with the Republican-led House of Representatives. As an example, he cited Jackson's decision to declare the shallow, concrete-lined Los Angeles River "navigable waters" as a way to protect it under the Clean Water Act.
"That's navigable? I mean, give me a break. ... It was almost comical," Eisenberg said, citing the case as "symbolic of how things started to move" with the Obama administration.
Fifteen Democratic senators -- including Barbara Boxer and Dianne Feinstein of California and Bill Nelson of Florida -- joined independent Sen. Bernard Sanders of Vermont in urging Obama last week to replace Jackson with someone who'll retain a focus on public health and the environment.
"We know that pollution can cause asthma attacks, heart and lung disease, cancer, damage to the reproductive system, strokes and premature death," they wrote in a letter to the president. "As we confront these numerous and growing threats to our health, our nation needs another strong leader at EPA who will work to craft bold solutions to these serious problems, as well as enforce the Clean Air Act and our other landmark environmental laws that protect public health."
Critics of the EPA are predicting tough times ahead for business.
In December, Inhofe said the agency "seems willing to appease the far left" and ignore any need for balance in environmental regulation.
"The result: devastating impacts on jobs and our economy, which can seriously harm public health," Inhofe said.
Last month, U.S. Chamber of Commerce President Tom Donohue said major EPA rules imposed during the last 10 years had cost more than $23 billion and that new ozone regulations might cost up to $90 billion. He said the federal government was issuing about 4,000 regulations each year and that the EPA might "ensnare roughly 6 million facilities in burdensome permitting requirements" if it moved to apply rules on greenhouse gas emissions beyond power plants and refineries.
"When you consider all the new rules pouring through the regulatory pipeline, and those still to come, it is staggering," Donohue said in his annual speech on the state of American business.
Ruckelshaus, famous for his role in the Watergate scandal as the deputy attorney general who resigned instead of following Nixon's order to fire a special prosecutor, made his mark in politics as a moderate Republican. But he said he'd voted for Obama twice, accusing his own party of abandoning environmental issues.
"They've become not only neutral on the subject but antagonistic to it. I think that's a very bad mistake, myself," Ruckelshaus said.
When environmentalism was more popular during the Nixon years, he recalled, four executives from the U.S. automobile industry came to Washington to try to stop the Clean Air Act from passing.
"They didn't get anywhere," Ruckelshaus said. "They simply misunderstood the strength of public opinion on the issue, and that was true of a lot of industrial leaders at the time."
Today, he said, special interests are better organized, better able to stop environmental regulations with arguments that jobs are at stake. He said history proved that it was harder to get Americans to accept more regulations when the economy was weak, and he predicted that there will be a growing appetite to tackle global warming as the economy improves."This is true all over the world," Ruckelshaus said. "Whenever people have the ability to feed, clothe and shelter themselves, then they begin to worry about some of these more esoteric issues, like the environment and public health."