Trump's EPA pick is currently suing the agency he would lead

President-elect Donald Trump has picked Oklahoma Attorney General Scott Pruitt - a man who is currently suing the Environmental Protection Agency - to lead it, part of a history that has encouraged the agency's critics and provided worry to environmental groups.

Beginning last year, Pruitt joined several other state attorneys general in suing the agency over the Clean Power Plan, policy drafted under the Obama administration and geared toward reducing pollution from the electricity sector.

That lawsuit is still ongoing, as The Washington Post has reported.

And it's not the first time Pruitt has been down this road.

A self-described "leading advocate against the EPA's activist agenda," Pruitt has brought lawsuits against the Obama-led EPA several times.

His approach drew the attention of The New York Times, which in 2014 published a story examining what it called the "unprecedented, secretive alliance" between Pruitt and several other Republican attorneys general and some of the top US energy companies to push back against the Obama administration's regulatory agenda.

The Times investigation uncovered emails in which the leaders of these energy companies drafted letters for Pruitt to send to the EPA - letters that essentially asked for "actions that could help increase the company's profits," as the Times put it.

In one such letter, Pruitt accused federal regulators of overestimating the amount of air pollution being emitted by energy companies who were drilling natural gas wells in Oklahoma. Emails uncovered by the Times revealed that letter was originally drafted by lawyers for one of the largest oil and gas companies in the state, Devon Energy. It was then "copied onto state government stationery with only a few word changes, and sent ... to Washington with the attorney general's signature," according to the Times.

David Rivkin, a constitutional litigator at the international law firm Baker Hostetler who represented Pruitt and the state of Oklahoma in the lawsuit against the Clean Power Plan, recently told the Post that he felt Pruitt would help ensure the EPA continues protecting Earth's natural resources while reducing federal overreach.

"General Pruitt has been the leader among the AGs in defending federalism, the key feature of our constitutional architecture," Rivkin told the Post. He also said he felt Pruitt would "ensure both environmental protection and constitutional fidelity."

You can view the letters on the New York Times here.