As Roger has just blogged, the Supreme Court in today’s Comstock decision has “turned an instrumental power, dependent on Congress’s other powers, into an independent power.” That is, Justice Breyer’s decision has imbued the Necessary and Proper Clause — which merely gives Congress the power to enact laws that are “necessary and proper” for “carrying into execution” one of the powers enumerated in Article I, section 8 — with independent authority to justify federal power. Thus, in effect, Congress has the power to do anything it deems “necessary and proper” (or, indeed “convenient or useful”), quite apart from whether that thing relates to an enumerated power or not. I explained here why this view — and Breyer’s elaboration on it during oral argument — is wrong.

Without exaggeration, the Comstock decision is one of the most harmful Supreme Court decisions in recent memory. If there is anything worse than the Court’s radical expansion of the Necessary and Proper Clause, it is that seven justices signed onto this sweeping pronouncement. While it isn’t surprising that Justice Breyer, joined by his “progressive” colleagues, would have such an expansive view of federal power, it is disconcerting that Chief Justice Roberts joined the majority opinion in its entirety. And while Justice Kennedy separately counsels that “the Constitution does require the invalidation of congressional attempts to extend federal power in some instances,” it’s hard to see what those instances are in the wake of Comstock. Justice Alito also has some qualms about the reach of the Necessary and Proper Clause but unfortunately is left satisfied that here “there is a substantial link to Congress’ constitutional powers” (adding yet another exception that swallows the constitutional rule on limited congressional power).

Only Justice Thomas, whose magisterial dissent is joined by Justice Scalia, sees today’s decision for what it is, the transformation of the Necessary and Proper Clause into a sort of federal police power, the existence of which the Court has long denied. As Thomas says, “the Constitution does not vest in Congress the authority to protect society from every bad act that might befall it.” (This is of course counter not only the Court majority but also the immortal words of President George W. Bush that “when somebody hurts, government has got to move.”)

About the only good thing about this opinion is that it declined to expand Congress’s power under the Commerce Clause — an alternative justification for the law at issue that the government offered unsuccessfully in the court below and which Solicitor General Elena Kagan abandoned before the Supreme Court.

For more coverage of Comstock, see Josh Blackman’s series of posts and Randy Barnett at the Volokh Conspiracy. Also, here is Cato’s brief on the case (which I summarize here) and my description of Kagan’s response to some of the points we raised.