The Supreme Court has ruled 7-2 that the federal government has the right to imprison sex criminals even after they have completed their sentences if the government determines they continue to pose a danger to the public. Dissenters were Justices Scalia and Thomas, who said that yes, sexual violence is a terrible thing, but there is simply nothing in the Constitution giving Congress the right to infringe an individual’s liberty to this degree. As Justice Thomas wrote in his dissent, “[T]he Constitution does not vest in Congress the authority to protect society from every bad act that might befall it.” Justice Thomas noted the potential for abuse in expanding the state’s police powers over individuals. He also said that what’s at issue is not what powers the Constitution should have granted to Congress, but what powers the Constitution actually has granted to Congress.

It’s a principled stand, to be sure, but I find myself pleased that the Court ruled as it did, given the dangers that certain sex criminals (e.g., child molesters) pose to society. Solicitor General Elena Kagan, in successfully arguing the government’s case before the Court, said this is analogous to the government’s right to hold prisoners who have a deadly and highly contagious disease after they finish their sentences, for the common good. That makes sense to me, but Justice Thomas’s dissent makes me worried that I’m too willing to yield on a key principle because I like the result of this judgement. From the Volokh blog, Jonathan Adler calls this ruling a major defeat for those seeking to establish limits on federal power.