Last week, I took a skeptical look at an argument by two attorneys general for the constitutionality of an individual mandate to buy health insurance. Part of the problem with that piece was that it didn't bother to address the crucial question: How does the Commerce Clause, which gives Congress the power to regulate interstate commerce, allow Congress to prohibit the decision to not purchase health insurance—something that involves no commercial transactions, much less commercial transactions across state lines, and which couldn't possibly involve interstate commerce anyway given that there's currently no way to buy insurance across state lines.
Today, Cato Chairman Robert Levy has a much clearer explanation of how the Supreme Court has ruled on Commerce Clause cases which involve neither commerce nor the crossing of state lines. In Wickard v. Filburn and Gonzales v. Raich, he explains, the gist of the Supreme Court's decisions was that "if the failure to regulate would undercut a federal regulatory regime, then [the Supreme Court is] going to permit it." But, he argues, the individual mandate is still uncharted territory; the federal government isn't merely telling individuals what they can't do, it's telling them what they must do, and what they must do is purchase a product from a private company. As I've noted frequently, the CBO has called the mandate "an unprecedented form of federal action," and Levy's analysis tracks with that assessment. I still don't think I'd put money on the Supreme Court actually striking down the mandate, but Levy's argument that they should is fairly convincing.
Jacob Sullum wrote about the crazy constitutional logic of the individual mandate here. Damon Root noted one legislator's lack of concern for the constitutionality of the mandate here and looked at how the mandate has revived debates about the Commerce Clause here.