EPA Chief Scott Pruitt has long been a controversial figure within the environmental community.

Facing an escalating series of scandals, EPA Administrator Scott Pruitt has become the latest member of the Trump Administration to resign, the president announced on Thursday afternoon.

The 50-year-old Cabinet member has been a controversial figure since he was nominated as head of the nation’s top environmental protection office. As Oklahoma Attorney-General, Pruitt had repeatedly sued the EPA and had called for its elimination. Once in office, he began rolling back a series of measures enacted not only by the Obama Administration but previous Republican presidents. Among other things, the EPA has begun moving forward with plans that were expected to roll back the Corporate Average Fuel Economy standards.

“Within the Agency Scott has done an outstanding job, and I will always be thankful to him for this,” President Trump said in a Thursday afternoon tweet announcing Pruitt’s departure. It did not, however, mention the reasons why the controversial head of the Environmental Protection Agency resigned.

(EPA Chief Pruitt announces plan to rollback CAFE. Click Here for the news.)

Pruitt has been taking fire from environmentalists since he was first named as the likely Trump EPA chief, his many critics arguing that he represented exactly the opposite of what the agency – created by Republican President Richard M. Nixon – stood for.

Pruitt seemed almost oblivious to the many scandals he was involved in during a barely 18-month tenure as EPA chief.

But it wasn’t specifically Pruitt’s position on environmental issues that ultimately drove him from office. It was his behavior in Washington that got him in trouble – and made him the target for a number of ongoing probes. One of the most embarrassing, at least for the Trump White House, came when it was revealed the EPA chief initially moved into a luxury Georgetown condominium owned by a well-known lobbyist, paying only a fraction of its market value in rent.

Pruitt also took heat for using an outsized security detail, for spending $43,000 on a sound-proof phonebooth for his office, for using government staff to run personal errands and, it was recently disclosed, for hiding some of his appointments with lobbyists working to roll back EPA regulations.

The constant drumbeat of headlines even seemed to overwhelm a president who routinely has dismissed criticism of his White House team as “fake news.” In a conversation with reporters on June 15th, Trump acknowledged, “I’m not happy about certain things,” before adding. “But he’s done a fantastic job running the EPA, which is very overriding.”

Others, including Texas Sen. Ted Cruz, routinely dismissed any concerns about Pruitt’s behavior as a left-wing conspiracy.

Whether Pruit recognized the problems has facing – or causing the White House – has never been clear. He routinely downplayed criticism, even during hostile questioning on Capitol Hill. And he appeared to be so confident in his position within the Trump inner circle that, earlier this year, Pruitt tried to convince the president to let him replace Attorney General Jeff Sessions, a cabinet member who has been a frequent target of public criticism by the Commander-in-Chief.

But Pruitt even stepped on toes at the White House, at one point approving raises for two close allies at the EPA despite the Oval Office decision not to grant those pay hikes,

Where Trump has had something of a Teflon quality, able to withstand even the most embarrassing of scandals, that wasn’t the case with Pruitt who seemed more of a magnet. While the president has won support from followers and many Republicans for questioning the concept of global warming, Pruitt’s similar position found him under fire even from some allies.

“It’s one thing after another with this guy,” Trump reportedly said, according to a close source quoted by the New York Times.

During barely 18 months, the Trump Administration has rescinded a wide assortment of environmental rules and regulations, many of them first implemented by the Obama Administration. They covered an array of issues, including air and water pollution, as well as the use of controversial chemicals in agriculture.

Earlier this year, meanwhile, Pruitt’s EPA finally announced the first steps in what was widely expected to be a rollback of the Obama-era CAFE standards that were set to reach 54.5 miles per gallon by 2025.

Ironically, even though many auto industry executives – including former Ford CEO Mark Fields – had called for relief in the early days of the Trump Administration, there seemed little open support when Pruitt finally moved ahead on April 2^nd, asserting the mileage rules were approved with “politically charged expediency, (and) made assumptions about the standards that didn’t comport with reality and set the standards too high.”

Ford, in particular, appeared to be backing off in the face of sharp criticism from environmental and consumer groups and polls showing the public strongly in favor of increased mileage requirements. But other automakers also stepped back.

(Fiat Chrysler backs off proposed CAFE rollbacks. Click Here for the story.)

What happens now is uncertain, though few expect to see a major shift in the Trump environmental approach – not when the EPA will, for now, be headed by Andrew Wheeler, Pruitt’s second-in-command. Wheeler’s appointment was as controversial as the now-ousted EPA chief considering he previously served as a lobbyist for the coal industry.

Meanwhile, a number of EPA staff members, at various levels, have stepped down, in protest or in frustration, with the administration’s policies and others are reportedly considering their options.

Stepping down from his EPA post may not help Pruitt at this point. He has been accused by one federal watchdog agency with violating the law by purchasing that soundproof phonebooth, and he now faces at least 13 federal investigations.

(Trump meets with automakers about CAFE, blasts NAFTA instead. Click Here for the story.)