After President George W. Bush’s National Energy Plan of 2001 encouraged the development of hundreds of new coal-fired power plants across the U.S., the Sierra Club created a program, Beyond Coal, to oppose these proposed new plants and prevent a surge in greenhouse gas emissions. My dissertation evaluates Beyond Coal’s level of success in meeting these goals, and the strategy it used to pursue them. I took a multimethod approach to this research, employing both quantitative, cross-case analysis and qualitative case studies. I gathered extensive data on the 235 proposed new plants challenged, to identify the characteristics of these cases and gain insight into why some succeeded while others failed. I supplemented this analysis with a set o...