For years, New York City insisted it did not have a pollution problem; the problem was the bad air coming in from New Jersey. But there is a federal remedy for just about every perceived wrong, and, in this case, it’s the EPA and the “good neighbor” provision of the Clean Air Act to the rescue. The provision supposedly gives the EPA power to oversee remedies when alleged pollution in one state blows into a neighboring state. A state that significantly contributes to another state’s failure to meet federal standards can be required to limit emissions by a commensurate amount.

Under the Clean Air Act, the regulation of air pollution was the primary responsibility of states and municipalities. The EPA’s 2011 cross-state pollution rule, however, allowed the EPA to issue implementation plans immediately, instead of waiting for the states to develop their own. The EPA also promulgated a one-size-fits-all standard that doesn’t recognize an individual state’s contribution to downwind pollution.

More than a dozen states are now challenging these EPA mandates in Environmental Protection Agency v. EME Homer City Generation. In a 2-1 ruling, the DC Court of Appeals struck down the EPA rule in 2012, holding that the Clean Air Act “did not authorize EPA to simply adopt limits on emissions as EPA deemed reasonable.” The U.S. Supreme Court heard arguments Tuesday.

The EPA rule was intended to implement the Obama administration’s anti-carbon agenda, so, naturally, Democrats decried the Court of Appeals’ decision – more so because a Bush appointee wrote the majority opinion. But it’s telling that the DC Circuit also denied en banc review (i.e., review by the entire bench). So we’re off to see the Supremes, who should note that not only does the EPA rule violate principles of federalism, but also that the DC Circuit rarely overturns EPA rules, showing how extreme were the rules being reviewed. But if arguments were any indication, the Supreme Court may grant “a healthy amount of discretion” to the EPA. That’s bad news.