Scott Pruitt, who repeatedly has sued the Environmental Protection Agency during his tenure as Oklahoma attorney general, declined to say Wednesday whether he would recuse himself from those ongoing cases if confirmed as the agency’s new leader.

Questioned by Sen. Edward J. Markey (D-Mass.) about whether he would avoid involvement in a series of ongoing cases against the EPA that he has been party to while in Oklahoma, Pruitt said he would rely on the advice of agency ethics lawyers.

“If directed to do so, I will do so,” he said.

“If you don’t agree to recuse yourself,” Markey said, “then you become plaintiff, defendant, judge and jury on the cases you are bringing right now as attorney general of Oklahoma against the EPA.”

The exchange was among several tense moments Pruitt encountered Wednesday about his fitness to run the agency, his close ties to the oil and gas industry, his views on climate change and even the water crisis in Flint, Mich.

Democrats on the Senate Environment and Public Works Committee grilled the 48-year-old former state lawmaker about his financial support from fossil fuel companies, which have given hundreds of thousands of dollars to Pruitt and political action committees associated with him.

Sen. Jeff Merkley (D-Ore.) displayed a 2011 letter Pruitt sent to the EPA saying it had overestimated air pollution from natural gas drilling — a letter largely written by lawyers for Devon Energy, one of Oklahoma’s largest oil and gas companies. He accused Pruitt of acting as “a direct extension of an oil company” rather than on behalf of ordinary Oklahomans.

Pruitt countered that he was not representing any one company but, rather, expressing the concerns of an entire industry in the state.

Pruitt also sought Wednesday to head off critics who call him a “climate denier” by acknowledging that “science tells us that the climate is changing.” But he added that precisely how much humans are contributing to the problem and what policy actions to take remain open “to debate and dialogue.”

It was a debate that Sen. Bernie Sanders (I-Vt.) embraced, challenging Pruitt about his lack of urgency regarding climate change, and on the role of the oil and gas industry in causing widespread earthquakes in the state of Oklahoma.

“Why is the climate changing?” Sanders asked, requesting Pruitt’s “opinion” about the matter.

“My opinion is immaterial,” Pruitt replied.

(Reuters)

“Really?” Sanders countered. “You are going to be the head of the agency to protect the environment, and your personal feelings about whether climate change is caused by human activity is immaterial?”

Pruitt said the EPA has a “very important role” to perform in regulating carbon dioxide emissions — an intriguing statement from a man who led the charge against the Clean Power Plan, the Obama administration’s main effort to cut carbon emissions. He said he would respect EPA’s “legal obligation” to tackle the issue. He also said “there is a time and a place” for EPA to use its authority to enforce regulations if states refuse to do so.

At the same time, he declined to commit to whether he would allow California to set its own emissions standards for automobiles that exceed federal limitations. Pressed by Markey and Sen. Kamala Harris (D-Calif.), Pruitt promised only that he would “review” such a policy.

Asked about the water crisis in Flint, Mich., Pruitt said he had not “looked at the scientific research” about what constitutes dangerous levels of lead exposure. (Health officials have long said there is no safe level of lead, especially in children.)

“That’s something I have not reviewed nor know about,” Pruitt said, though he added, “I would be concerned about any level of lead going into the drinking water or, obviously, human consumption.”

[‘If I could afford to leave, I would.’ In Flint, a water crisis with no end in sight.]

Pruitt told lawmakers Wednesday that, if confirmed, he plans to steer the agency away from what he sees as an era of overzealous and unlawful regulation during the Obama years. He said his EPA would be one that respects the authority of states and is open to a “full range of views.”

Pruitt also dismissed the idea that if someone supports oil and gas interests, he can’t also favor environmental protection. “I utterly reject that narrative,” he said. “It is not an either-or proposition.”

Pruitt’s tenure as attorney general in Oklahoma has been marked by his role in opposing the Obama administration’s key initiatives, often arguing that the executive branch was overstepping its constitutional authority and circumventing the role of Congress.

Pruitt has been a leading voice among a group of Republican attorneys general who also sued over issues including the Affordable Care Act, Wall Street reforms and immigration. But he has been particularly aggressive in attacking the EPA’s efforts, suing the agency to challenge its authority to regulate toxic mercury pollution, smog, carbon emissions from power plants, and the quality of wetlands and other waters.

Pruitt received broad support Wednesday from Republicans in the Senate, who are expected to approve his nomination. The committee’s chairman, Sen. John Barrasso (R-Wyo.), said Pruitt would help to quell the “regulatory zeal” of the past eight years. Sen. Dan Sullivan (R-Alaska) called Pruitt the right person to provide the “course correction” EPA needs.

[At EPA nominee’s hearing, money becomes a weapon for both parties]

Meanwhile, Pruitt’s nomination has galvanized environmental advocacy groups, who note that Pruitt dismantled a specialized environmental protection unit that had existed under his predecessor and poured resources into a new “federalism unit” aimed at challenging “unwarranted regulation and systematic overreach” from Washington.

They argue that his close ties to the oil and gas industry and his hostile history with the EPA make him a disastrous choice to run an agency created to protect ordinary Americans from pollution.

Even as Pruitt spoke, scientists on Wednesday were declaring 2016 the hottest year on record, making it the third year in a row to earn that title.

[U.S. scientists officially declare 2016 the hottest year on record.]

The small hearing room had just a few seats open for the public on Wednesday, frustrating a large group of protesters who’d shown up. Protesters dressed as a BP technician and an oil-stained bird did make it inside, grumbling about the security.

The protester in BP get-up, carrying a fake can of oil, was removed by security after shouting that Pruitt would gut the EPA.

Throughout the day, a flood of social media posts, emails, online ads and television commercials from advocacy groups, lawmakers and industry representatives urged senators to reject Pruitt because he will fail to protect the environment, or to confirm him because he will end the EPA’s overaggressive regulations.

Pruitt has repeatedly framed his EPA opposition as driven not by ideology but by constitutional questions over the separation of powers: Congress makes the laws. Agencies administer them. And states enforce them.

“Rule of law matters,” he said Wednesday. “Regulators are supposed to make things regular, to fairly and equitably enforce the rules, and not pick winners and losers.”

Chris Mooney contributed to this report.