In 1992, the Court delivered it’s opinion in NY vs United States, which ruled parts of a Congressional law regarding the handling of radioactive waste to be unconstitutional.
This is one of the most comprehensive treatments of federal legislation and administrative procedures ever.
The Court basically B-slapped Congress big time, and NY vx US has been the basis of a number of decisions since then, Lopez being only one.
States are not mere political subdivisions of the United States. State governments are neither regional offices nor administrative agencies of the Federal Government. The positions occupied by state officials appear nowhere on the Federal Government’s most detailed organizational chart. The Constitution instead “leaves to the several States a residuary and inviolable sovereignty,” The Federalist No. 39, p. 245 (C. Rossiter ed. 1961), reserved explicitly to the States by the Tenth Amendment.
NY vs United States, 505 US 144, 188
If Obama was unsure of certain provisions that might render his crown jewel unconstitutional. He should have used the Line Item Veto that the Republican controlled House passed with Unanimous Consent and was signed by a Democrat president.