Jost on the Constitutionality of the ACA -- and Medicaid

Tim Jost has a piece up on the New England Journal of Medicine's website entitled "Is Medicaid Constitutional?"  It begins:

Although the media and the U.S. public focused primarily on the minimum-coverage requirement, or individual mandate, during the recent oral arguments in the challenges to the Affordable Care Act (ACA) before the Supreme Court, the most important issue before the Court may well be the constitutionality of the ACA's Medicaid expansion. There are potential alternatives to the minimum-coverage requirement, but a finding that the Medicaid expansion is unconstitutional could threaten all federal spending programs that set minimum participation standards. Indeed, as Justice Stephen Breyer observed during the oral argument, if the plaintiff's argument is accepted, then “Medicaid has been unconstitutional since 1964.”