The Trump Administration has taken numerous actions that appear hostile to scientists, scientific research, and scientific data, leading some observers to assert that a war on science is underway. A more precise characterization is that the Trump Administration is engaging in a war on regulatory science, as these actions take aim specifically at regulatory science - i.e., knowledge production and synthesis carried out by EPA and other government agencies in the course of developing government regulations. The Administrative Procedure Act ("APA") and other laws may constrain some aspects of the war on regulatory science, provided that they are subject to judicial review. Internal administrative law and agency norms also can promote rule of law values, but their success depends largely on the good faith of executive branch actors and the willingness of Congress and the public to push back when norms of administrative legality are ignored. Absent such pushback, the Trump Administration's war on regulatory science could lead to irrational policies and threaten democratic governance.

The conventional account of most U.S. environmental regulation goes something like this: cooperative federalism schemes accommodate state and federal interests while tapping into the respective strengths of centralized and decentralized regulation. In cooperative federalism arrangements, the federal government sets minimum environmental standards and invites the states to participate in achieving them, even by setting their own more stringent standards. In recent years, however, states and the federal government have displayed a distinct lack of cooperation on environmental matters. With increasing frequency, they turn to the courts to resolve environmental policy disagreements. Under the Obama Administration, Texas emerged as a leading litigant in opposition to federal environmental policies. Under the Trump Administration, California has assumed a similar role. Though these recent suits have attracted much attention, state-versus-federal lawsuits are not a new phenomenon. As this Article demonstrates, states and the federal government have clashed in the courts almost since the beginning of the modern era of environmental law. State-initiated environmental lawsuits against the federal government can be sorted into three categories: (1) challenges to the federal government's handling of public resources, (2) disputes over state prerogatives under cooperative federalism statutes and preemption provisions, and (3) litigation over national policy. Suits in the third category, which have exploded in recent years, have raised the greatest concerns about state standing and the appropriateness of such suits. Standing doctrine, however, generally does not bar such suits, and these suits may not be as problematic as might first appear. Even if states did not sue, private parties would likely challenge the same federal actions. Rather than causing political polarization, state suits are more likely a symptom of an already polarized society. Ultimately, state suits against the federal government might be viewed not as a problem, but as an important mechanism for articulating states' concerns, promoting accountability, and maintaining checks and balances against excessive federal power.