Holding: The states repeal of the covenant constitutes an unconstitutional impairment of expected contractual rights/benefits. Why:
When a State impairs the obligation of its own K, the reserved powers doctrine has a different basis. The k clause does not require a State to adhere to a K that surrenders an essential attribute of its sovereignty.
TEST: (1) Is the contractual impairment “reasonable and necessary” to
(2) “support an important public purpose”