The CSSN Working Group on Climate Conflict in the U.S. States focuses on climate policy activity and inertia in U.S. subnational governments. In the absence of federal leadership on climate change in the United States, subnational governments often serve as “laboratories of democracy,” producing innovative climate change mitigation and adaptation policies. Despite high levels of action in some states, staunch opposition to climate policy has led many states to enact symbolic policy that lacks the teeth to meet ambitious goals or mandates. Moreover, weak executive actions are immediately reversed with changing governors, and the climate denial and/or delay movement continues to flex its political muscle in the states. This working group aims to more fully understand the challenges states face in their pursuit of climate mitigation policy through descriptive and empirical work. In particular we intend to understand how variation in state-level institutions, interest group populations, public opinion, and political contexts can lead to policy inertia. We also plan to offer solutions to political stalemates on climate policy in the states.