National Federation of Independent Business v. Sebelius

Majority reasoning

Chief Justice Roberts, writing for the Court, first held the Anti-Injunction Act did not bar the suit because Congress labeled the payment a "penalty," not a "tax," for statutory purposes. On the Commerce Clause, the majority reasoned that Congress may regulate existing commercial activity but cannot compel individuals to enter commerce by purchasing a product, because the Constitution's grant of power to "regulate" commerce presupposes something already being regulated; allowing regulation of inactivity would grant Congress unlimited power to mandate purchases of virtually anything, including broccoli. The Necessary and Proper Clause likewise could not save the mandate because it would let Congress create the very predicate for regulation rather than merely carry out an enumerated power. However, because a statute must be read to avoid unconstitutionality if fairly possible, the majority construed the mandate as a tax: the payment is tied to income, capped, collected by the IRS without criminal enforcement, and produces revenue, so it functions as a tax even though Congress called it a penalty. On the Medicaid expansion, the majority held that threatening states with loss of all existing Medicaid funds unless they adopted a dramatically expanded program was unconstitutionally coercive under the Spending Clause, transforming Medicaid into a new program rather than a permissible amendment, so the remedy was to bar the Secretary from withdrawing existing funds for noncompliance with the expansion while leaving the rest of the Act intact.

Dissent reasoning

Justice Ginsburg, joined in relevant part by Justices Sotomayor, Breyer and Kagan, dissented in part, arguing that the mandate should also have been upheld under the Commerce Clause because the uninsured as a class substantially affect the national health-care market through cost-shifting, and Congress reasonably addressed this national problem after guaranteed-issue and community-rating reforms without a mandate caused market collapses in several states. She argued the majority's activity/inactivity distinction has no basis in constitutional text or precedent and resembles discredited pre-New Deal formalism, and that the Necessary and Proper Clause plainly supported the mandate as integral to the guaranteed-issue and community-rating reforms. On Medicaid, she argued the expansion was a permissible amendment to an evolving program that states were on notice could change, and that withholding funds for noncompliance was not coercive; she agreed only that if the Court found withholding unconstitutional, the proper remedy was to bar only the withholding, not to strike the whole expansion. Justice Scalia, joined by Justices Kennedy, Thomas, and Alito, dissented in full, arguing the mandate exceeds the commerce power because compelling entry into commerce is fundamentally different from regulating existing activity, that the mandate cannot be read as a tax because Congress unambiguously called it a penalty and structured it as a legal requirement with exemptions inconsistent with a tax, and that the Medicaid expansion is coercive and inseverable from the rest of the Act, meaning the entire Affordable Care Act should fall. Justice Thomas separately dissented to reiterate his view that the "substantial effects" test itself is inconsistent with the original understanding of the Commerce Clause.