Some will immediately claim that today's decision in United States v. Comstock bodes ill to pending challenges to the individual health insurance mandate, but this would be a mistake. It is one thing to uphold as "necessary and proper" a law confining sexual predators who were already incarcerated pursuant to the enumerated powers of Congress. It is quite another to impose a mandate on every citizen of the United States as necessary and proper to its power "to regulate commerce . . . among the several states." The justices who sided with the government today cannot all be counted on to uphold the unprecedented claim of federal power to require that all persons engage in economic activity.