The logic of Justice Roberts's opinion suggests that once states adopt new Medicaid, the program immediately becomes the old program forthepurposesofthelaw and then states can't leave.
The United States also has a Countervailing Duty law, which for 22 years up until 2007 had not been applied to imports from countries that, forpurposesofthe antidumping law, were deemed NMEs.
There was serious skepticism at that time that the laws ofthe state where the DAPT was formed would trump for choice-of-law purposesthe laws of where the debtor or trust assets were located.