Critics label Andrew Wheeler a climate skeptic opposed to expansive environmental rules, whose years on Capitol Hill were spent supporting the work of like-minded Republican lawmakers.

But some former Senate environment committee aides who worked with Wheeler describe a policy wonk who cooperates with all political stripes, and at times worked to promote measures for clean water, clean air, and even an ill-fated attempt to use an emissions trading program to cut air pollution.

In his first month on the job, the acting head of the Environmental Protection Agency has been classified as everything from a policy nerd to Scott Pruitt in sheep’s clothing.

Now Wheeler gets the chance to speak for himself, testifying before Congress Aug. 1 for the first time as acting EPA administrator. The setting will be familiar: the Senate Environment and Public Works Committee, where Wheeler worked for more than a dozen years, from the mid-1990s until 2009.

In interviews with Bloomberg Environment, 11 lawmakers and former staffers who worked with the GOP aide on the environment committee recalled Wheeler as tough but not always intractable on legislation.

He battled to defeat Senate climate bills but helped cut deals to move other legislation including Safe Drinking Water Act amendments, three highway bills, water conservation measures, and diesel reduction legislation.

Wheeler arrived on the Hill as a Republican aide early in the Clinton administration, staying on through the Bush years and departing with the arrival of President Barack Obama. Most of his tenure was split between staff director for a clean air subcommittee and later working as committee staff director and general counsel.

His former colleagues suggest that based on his work style, he’ll approach the job of EPA chief very differently from Pruitt, the EPA administrator who resigned under pressure July 6. They say to expect Wheeler to build on relatively cordial relationships with Democratic senators and to put his Capitol Hill expertise on environmental statutes to work running the agency.

Human Impact

On climate change, Wheeler has recently acknowledged there may be some human role in warming the planet, but he questions how much.

“I believe that climate change is real and that humans have an impact on the climate,” he wrote the committee in 2017, before being confirmed EPA deputy administrator.

But he was circumspect at his confirmation hearing for that job, saying the human impact isn’t “completely understood.”

But Wheeler’s long association with Sen. Jim Inhofe (R-Okla.), who has called climate change a hoax and was Wheeler’s boss for most of his time at the committee, worries some Democrats and environmental groups. Wheeler’s 2009 tweet—"Climate alarmists refuse to debate or leave their facts at home when they do"—hasn’t helped.

In 2010, Wheeler said the United Nations’ Intergovernmental Panel on Climate Change had “blurred the lines between science and advocacy.” The IPCC, the UN’s expert body on climate science, has long said fossil fuel combustion and other human activities are a significant culprit in warming the planet.

‘Upfront Climate Denier’

Former Sen. Barbara Boxer (D-Calif.), who worked with Wheeler for years at the environment committee, said she doubts his thinking has changed. “Andy Wheeler is just an upfront climate denier,” Boxer said in a recent interview. “Andy Wheeler will give 100 percent of his attention to undoing the EPA. Trust me.”

Wheeler did not respond to request for an interview on his climate views.

Boxer, who retired two years ago, added that she “never had a bad word with Andy Wheeler” in the committee. But she believes that Wheeler, unburdened by the ethics baggage that sunk Pruitt, could quietly escalate President Donald Trump’s deregulatory playbook.

“What do they say about magicians—when they’re doing a trick, they try to get you to watch the hand up in the air,” Boxer said. “But it’s the other hand, meanwhile, that’s doing all the work.”

‘Knows His Stuff’

Other current and former committee members, including Sen. Ben Cardin (D-Md.) and Sen. Lisa Murkowski (R-Alaska), said Wheeler is tough but rarely inflexible.

Wheeler, who arrived at the environment committee after four years in EPA’s chemicals office, gets high marks from some Democrats for backing legislation to further reduce diesel emissions. Wheeler also helped push an unsuccessful Bush administration-backed effort in 2005 to revamp Clean Air Act regulation of power plants that proposed using emissions trading to cut air pollutants.

Former environment committee GOP deputy staff director Chris Hessler, who worked with Wheeler during the Bush era, said Wheeler’s legislative knowledge can’t be overstated. “He knows substance and detail, and he knows the process,” Hessler said. “Andy knows his stuff.”

Hessler said Wheeler has gotten a bad rap as an opponent of environmental regulation and is unfairly painted “the coal industry lobbyist” for representing Murray Energy Corp., among the largest U.S. coal mining companies. Wheeler lobbied for the law firm Faegre Baker Daniels, where he worked for much of the last decade.

“He has a deep understanding of the interactions between all of the different actors in these [political] ecosystems in ways that not everyone outside of Washington would understand,” Hessler said.

‘Nose-to-the-Grindstone Nature’

Ryan Jackson, EPA’s chief of staff and a former environment committee GOP staff director, said Wheeler’s experience negotiating legislation at the committee level is now key to his approach in running the agency.

Wheeler’s “appreciation and recognition of what is practical to do, coupled with his hard working nose-to-the-grindstone nature and temperament is all going to lend to his success at EPA,” Jackson told Bloomberg Environment in a July 30 interview.

And relationships the acting EPA head has built with senators, in some cases dating back decades, will help, Jackson said. “I think that’s absolutely true, in any situation where there’s a history of a professional relationship, where two sides know each, it gives you a tremendous head-start,” he said.

‘Kind of Wonky’

Murkowski, once an environment committee member who heads the Senate energy committee, recalls Wheeler as “in the weeds” and “kind of wonky.”

“There is a general consensus that he is a very intelligent man,” she said.

“He’s got a clearly more transparent view of how he thinks the agency needs to be run” than Pruitt, Murkowski said, which “would go a long way” toward rebuilding strained relationships with senators and helping to boost flagging EPA morale.

Sen. Susan Collins of Maine, the lone Republican to vote against Pruitt’s nomination but for Wheeler’s confirmation as EPA deputy, said: “I first of all would like to see him fulfill the mission of the agency, which Scott Pruitt was never committed to.”

She added: “I am certain that he will adopt ethical standards in his spending and behavior,” though she hopes to steer Wheeler to boost “morale at the agency, since there was a real exodus during Scott Pruitt’s brief term.”

Juggler or Magician?

Hessler said Wheeler seeks out other views on environmental policy, knows the importance of seeking feedback from political and career EPA staff and Congress, and should be adept at juggling the views of political and career EPA staff even as he seeks to manage tense relationships with Senate Democrats.

But Boxer paints a picture of a political player with a bit of a stubborn streak. She recounted “one funny” interaction shortly after a new Democratic Senate majority awarded her the committee gavel in 2007.

“He did not want to move out of his suite,” an office near the committee traditionally awarded to the majority, Boxer said. “And we kept saying, ‘Andy, please, you have to get us into that office.’ And he’d say, ‘No. The next election we’re going to take it back.’”

Former aides who confirmed Boxer’s account said it took months before Wheeler vacated the office. But Jackson, the EPA chief of staff, disputed that account, saying Wheeler offered during the transition to move staff while leaving any office furniture moves for later.

“Andrew has never conducted himself in a petty manner. Everybody knows that,” Jackson told Bloomberg Environment, adding that he doubted Wheeler would have suggested he should stay through the next Senate election, which was two years away.

“That would be a funny thing to say—and we would have been very wrong,” Jackson said. “Because we didn’t take it back until 2014.”