While processes of policy change have received great scholarly attention, policy dismantling as a specific type of change has not yet been thoroughly studied. This might be due to low empirical visibility. Although policy dismantling has been rare in environmental policy, it is getting more relevant as environmental legislation tightens and places increasing burdens on polluting industries. This got obvious in the United States during the Bush Presidency where several attempts to dismantle environmental programs occurred. In order to improve our understanding about the circumstances under which environmental policies get dismantled, we analyze the case of the New Source Review (NSR). The NSR requires industries to install modern pollution control technologies in stationary sources of air pollution like coal fired power plants and refineries. NSR regulatory provisions require these sources to install pollution control when they expand capacities and increase emission levels. Between 2001 and 2007 several attempts to weaken the regulatory stringency of this program occurred. The Bush Administration proposed both legislative and as rule changes which dismantled the regulatory stringency of the Clean Air Act. The analysis of actors’ motivations to dismantle environmental regulations as well as institutional constraints limiting and/or impeding dismantling will improve our theoretical and empirical understanding of dismantling processes. By looking at NSR dismantling pressures and processes we examine under which conditions political actors engage in the dismantling of environmental policies and what factors influence the success of dismantling attempts.