The Liberty of Free Riders: The Minimum Coverage Provision, Mill’s ‘Harm Principle,’ and American Social Morality by Jedediah Purdy and Neil Siegel:

In this Article, we show that cost-shifting and adverse selection problems link the federalism dimension of the debate over the Affordable Care Act to the doctrinally separate and suppressed individual rights dimension. As the scope of these free-rider problems justifies federal power to require individuals to obtain health insurance coverage, so the very existence of the free-rider problems illuminates the difficulty of arguing directly — as opposed to indirectly through the Commerce Clause — that the minimum coverage provision infringes individual liberty. The interdependence between some people’s decisions to forgo insurance and the well-being of other people means that refusing insurance is far from being a purely self-regarding action. For reasons rooted in this interdependence, serious obstacles confront anyone who aims to establish that the liberty claims of free riders should be constitutionally or morally decisive.

We identify these obstacles to recognition of the claimed liberty interest with help from law, economics, and philosophy. First, we show that an economic substantive due process objection to the minimum coverage provision is doctrinally unavailable. Indeed, its unavailability explains why opponents of the provision take the less straightforward doctrinal approach of recasting the Commerce Clause in libertarian terms. Second, we invoke the long-standing tradition of argument in economics that market failures justify government regulation.

Finally, we draw from the “harm principle” of John Stuart Mill’s On Liberty. Mill’s deep commitment to libertarianism, which reflects the same anti-authoritarian spirit that moves many libertarians today, does not condemn the minimum coverage provision. This is because Mill’s criterion categorically forbids only paternalism in law-making, and the provision is justified on non-paternalistic grounds. When the regulation under consideration is not paternalistic, Mill’s libertarianism points explicitly to law and social morality to resolve boundary questions about what members of a society owe one another. In our judgment, these considerations — from federal and state safety net programs to charitable hospital practices — weigh in favor of the permissibility of the minimum coverage provision.

This is what the case is about. Not the commerce clause or the anti-injunction act.