The Illinois General Assembly does not possess "reserved sovereign powers" to diminish a constitutionally-protected pension. The state's chronic underfunding of its public pension systems for decades cannot warrant the impairment or diminishment of public employees' pension benefits and rights.
Fliter, John A. and Derek S. Hoff. Fighting Foreclosure: The Blaisdell Case, the Contract Clause, and the Great Depression. Kansas: the University Press of Kansas, 2012.