Earlier today the Supreme Court declined to take up the case of Alderman v. United States, which centered on whether the Commerce Clause allows Congress to forbid violent felons from buying, owning, or possessing body armor. In a notable move, Justice Clarence Thomas dissented from this decision, arguing that by failing to take up the case, “the Court tacitly accepts the nullification of our recent Commerce Clause jurisprudence.” That jurisprudence includes United States v. Lopez (1995), where the Court struck down the Gun-Free School Zone Act for exceeding Congress’ authority to regulate interstate commerce. In Thomas’ view, the lower court’s ruling in Alderman failed to take Lopez into account, and by allowing that flawed decision to stand, the Supreme Court permitted a ruling whose “logic threatens the proper limits on Congress’ commerce power and may allow Congress to exercise police powers that our Constitution reserves to the States.”

More importantly, Justice Antonin Scalia joined Thomas’ dissent. Remember that these two were on opposite sides of the Court’s notorious 2005 decision in Gonzales v. Raich (2005), with Scalia agreeing with the majority that medical marijuana cultivated and consumed entirely within one state nonetheless counted as commerce “among the several states.” So by signing on here, rather than simply keeping his vote secret like the other seven justices, Scalia has sent a pretty clear signal that, Gonzales notwithstanding, he still believes the Commerce Clause places a few genuine limits on congressional power. We'll have to wait and see if he thinks those limits extend to ObamaCare's individual insurance mandate.