On Monday the Supreme Court ruled in Michigan v. Environmental Protection Agency, a lawsuit concerning the agency’s duty to adhere to the Clean Air Act’s “appropriate and necessary” standard when issuing and enforcing regulations. The EPA published mercury and air toxin standards in 2012 that, by the agency’s own estimates, would cost the economy close to $10 billion annually. But today five justices — Antonin Scalia, John Roberts, Clarence Thomas, Samuel Alito and Anthony Kennedy — held that the “EPA interpreted §7412(n)(1)(A) unreasonably when it deemed cost irrelevant to the decision to regulate power plants,” handing conservatives a rare win at the conclusion of an otherwise unfriendly term. The agency, though clearly disgruntled, responded with little more than a shrug. “EPA is disappointed that the Court did not uphold the rule, but this rule was issued more than three years ago, investments have been made and most plants are already well on their way to compliance,” said EPA spokeswoman Melissa Harrison. In other words, good luck stopping the rule’s intended effects. That indifference to constitutional Rule of Law is exactly what Justice Thomas alluded to in his concurring majority opinion: “[W]e seem to be straying further and further from the Constitution without so much as pausing to ask why. We should stop to consider that document before blithely giving the force of law to any other agency ‘interpretations’ of federal statutes.” We can think of a few other cases that logic applies.