As Lisa Jackson gets ready to step down as head of the EPA shortly after the president's inauguration later this month, she is being hailed by environmentalists for pushing through the toughest new air and water pollution rules in over two decades, and speaking out on climate change in an administration that has largely avoided confronting the issue head-on.
Jackson is admired even by some of her critics. Republican James M Inhofe of Oklahoma, a leading Senate opponent of environmental legislation, referred to the charming Jackson as "my favorite bureaucrat".
But not everybody is sad to see the EPA administrator go. During the recent election campaign, Mitt Romney called for Jackson's resignation, and some Republicans in Congress have accused her of waging a "war on coal". Jackson's EPA drafted regulations that limit mercury emissions from coal-fired power plants. She also initiated a sweeping agency review of the impact of mountaintop removal in states like West Virginia and Kentucky, a practice that dumps raw mining waste into wetlands and streams.