The Paris Agreement ushered in an era of climate governance underpinned by a polycentric theory of change, emphasizing experimentation, collaboration, and innovation while downplaying political contestation, power asymmetries, and the need for regulatory action by the state. This article explores the roles the state plays in polycentric climate governance, focusing on the tension between the regulatory state, where authorities set, monitor, and enforce rules, and the orchestrating state, which facilitates collaboration with nonstate actors to induce behavioral change. Using decarbonization in Sweden as an illustrative case study, the article synthesizes the results of two research projects evaluating the promises and limits of polycentric climate governance. The results problematize the view that Sweden is a forerunner in climate governance, suggesting that while the Swedish government has mobilized support from important industries and cities in favor of decarbonization, that support may be insufficient to achieve necessary societal transformation for deep decarbonization. Finally, the study reflects on the conditions necessary for polycentric governance to effectively decarbonize society, highlighting the pivotal role of the regulatory state.