As it happens, today the Court hears separate arguments on Medicaid, and the themes in that controversy dovetail with those of the individual mandate. Just as the Court may rule that commerce powers are broad but not unlimited, the same is true for the spending power.

Florida and 25 other states contend that ObamaCare’s conversion of this voluntary program originally intended for the poor into all-purpose insurance for tens of millions of people is unconstitutional coercion. By commandeering the states and their taxpayers as de facto arms of the federal government, the Administration has abrogated the system of dual sovereignty as surely as it has by claiming police powers.

Medicaid was created in 1965 as a cooperative federal-state partnership. States could opt in, or not, and there were still holdouts as late as 1982. The program has expanded greatly over the years to the point that it is now the largest component of most state budgets. But Governors and legislatures have always had some measure of flexibility and independent control.

The Affordable Care Act obliterates this status quo and forces states to add everyone up to 138% of the poverty level to the rolls. The feds will pick up most of the new costs through 2020, though the states are still on the hook for between $20 billion and $43.2 billion in new costs, and much more into perpetuity.