The fact is that not since 1937 has the Court turned down the use of the Commerce Clause as a basis for Congressional intervention in a major national economic concern — which of course neither the Gun-Free School Zones Act nor the Violence Against Women Act were. Activity/inactivity is a new basis for limitation and has no anchor in our jurisprudence. That is why Roberts’s opinion was not conservative but radical. I have my doubts about the political and economic virtues of the ACA, but am appalled at this radically reactionary new doctrine.
And as for the reversion to Butler and pre-1937 Spending Clause jurisprudence, the practical effects may be profound and all bad. It is even bad contract law.