In a 5-4 decision yesterday, the Supreme Court struck down the Obama Administration EPA’s signature “Mercury and Air Toxic Rule,” which regulates emissions by fossil-fuel-fired power plants. Before regulating, EPA was obligated to decide whether regulation under one the Act’s most burdensome programs was “appropriate and necessary.” EPA interpreted that language to preclude it from considering the costs of regulation—some $10 billion per year, in exchange for $4 million or so in direct benefits. That interpretation, the Court decided, was ludicrous.
The decision may well leave the Obama climate agenda in tatters. Why that is requires a bit of explanation. In the usual case when the Court finds a rule to be unlawful, it vacates the offending action—in other words, deprives it of legal force. But that’s not what the Court did here. Instead, it sent the case back down to the D.C. Circuit for further proceedings, knowing full well that that court will follow its usual practice of “remand without vacatur”—in other words, let the agency fix any flaws in its rule while leaving the rule in place.