On September 11, 2013, Constitutional Accountability Center filed an amicus curiae brief in the Supreme Court in support of the government in Environmental Protection Agency v. EME Homer. For more than 50 years, the federal government has sought to mitigate interstate air pollution and promote healthy air quality. At issue in Homer was whether the Environmental Protection Agency (“EPA”), in its attempt to mitigate the cross-state, spillover effects of air pollution, exceeded its authority under the Clean Air Act (“CAA”).

To enforce an important provision of the CAA, the EPA promulgated the Transport Rule, which sets limits on the emission of pollutants in upwind states that “significantly contribute” to keeping downwind states from meeting federal air quality standards. Following a challenge to the Transport Rule brought by several upwind states and various industry groups, a divided panel of the U.S. Court of Appeals for the District of Columbia Circuit invalidated the Transport Rule in a decision that ignored the plain text of the CAA and second-guessed the expert policy judgments of the EPA. The EPA appealed that decision, and the Supreme Court agreed to hear the case.

Our brief demonstrated that the Constitution’s text, history, and structure support Congress’s power to pass laws that address genuinely national problems like interstate air pollution and bolster EPA’s authority to enact regulations that carry out those laws. The Framers assembled in Philadelphia to “form a more perfect Union” – more perfect than the British tyranny against which they had revolted and more perfect than the flawed Articles of Confederation under which they had lived for a decade since declaring independence. Concerned with creating a responsive, effective, energetic national government, the Framers granted Congress broad power to enact legislation on subjects and concerning problems that are federal by nature, and in cases in which states prove “separately incompetent” – a structural principle embodied in Resolution VI, a resolution adopted by the delegates of the Constitutional Convention declaring, in part, that Congress should have authority “to legislate in all Cases for the general Interests of the Union,” and translated into constitutional provisions (specifically, the powers granted to Congress in Article I).

The complex, interstate problem of air pollution is a challenge that is precisely the sort of national issue the architects of our Constitution intended Congress to solve. Air pollution, which inevitably crosses state borders, is a truly national problem that demands a national solution. Under the CAA, while the EPA establishes national standards for air pollution, states are given the flexibility to implement their own clean air policies to meet these federal standards. Only when states fail to comply – as was the case in EME Homer – does the EPA step in to issue its own plan. Accordingly, the CAA and the Transport Rule are perfect examples of our Founders’ vision of cooperative federalism in action and how the federal government can use its constitutionally granted authority to solve complex interstate problems while respecting the role of the states.

CAC’s brief urged the Court to uphold the EPA’s Transport Rule and reverse the D.C. Circuit’s decision. The Court heard oral argument in Homer on December 10, 2013.

On April 29, 2014, in a 6-2 ruling, the Supreme Court – as we had urged – upheld the EPA’s Transport Rule, concluding that it was a valid means of carrying out the CAA’s “Good Neighbor” provision. The Court recognized, as CAC’s brief explained, that interstate air pollution is the quintessential example of the kind of national problem the Framers designed our federal government to address. In the majority opinion authored by Justice Ginsburg, and joined by Chief Justice Roberts and Justices Kennedy, Breyer, Sotomayor, and Kagan, the Court determined that the “EPA’s cost-effective allocation of emission reductions among upwind states . . . is a permissible, workable and equitable interpretation” of the Clean Air Act. Justice Scalia issued a dissent, joined by Justice Thomas; Justice Alito was recused from the case.