He helped win a unanimous victory before the U.S. Supreme Court in Environmental Defense v. Duke Energy, a landmark Clean Air Act decision. Jaffe is the lead attorney representing a coalition of organizations challenging Dominion Power's proposal for a coal-fired power plant in the southwest Virginia mountains. He teaches environmental law and federalism at the University of Virginia Law School. He serves on the board of governors for the Environmental Law Section of the Virginia State Bar, and is on the board of the Virginia Conservation Network.