This Essay addresses a gap in the federalism literature. Scholars have offered two distinct visions of federal-state relations. The first depicts states as rivals and challengers to the federal government, roles they play by virtue of being autonomous policymakers outside the federal system. A second vision is offered by scholars of cooperative federalism, who argue that in most areas states serve not as autonomous outsiders, but supportive insiders – servants and allies carrying out federal policy. Legal scholarship has not connected these competing visions to consider how the state’s status as servant, insider, and ally might enable it to be a sometime dissenter, rival, and challenger. The literature has not developed a vocabulary for describing how states use regulatory power conferred by the government to resist federal policy, let alone a full account of the implications of this practice. It has thus neglected the possibilities associated with what we call “uncooperative federalism.” In this Essay, we provide an initial descriptive and normative account of this undertheorized aspect of our federalism. We also explore what a strong commitment to uncooperative federalism would mean for the doctrines on commandeering and preemption, offering some counterintuitive conclusions about the ways in which weakening the protections for state autonomy might push states to engage in stronger forms of dissent.