An amazingly wrong statement. In just about every situation, the federal constitution applies to the states as well. In fact, this very point has been litigated in Virginia, the site of this dispute:
"Addressing the interrelationships between the impairment of contracts and the police power of a state, the Supreme Court has ruled as follows: "The contract clauses of the Federal Constitution and the Virginia Bill of Rights protect against the same fundamental invasion of rights." 1 A. Howard, Commentaries on the Constitution of Virginia 203 (1974). The General Assembly "shall not pass any law impairing the obligation of contracts." Va. Const. art. I, § 11. See U.S. Const. art I, § 10 ("No State shall . . . pass any . . . Law impairing the Obligation of Contracts.") The Virginia contract clause has been interpreted by this Court in a manner similar to the treatment of the federal clause by the United States Supreme Court. A. Howard at 207."
http://64.233.167.104/search?q=cache:pBjzDo4kq7MJ:www.courts.state.va.us/opinions/opncavwp/2596991.doc+virginia+impairment+of+contracts&hl=en
Your argument seems a non sequitur. The Constitution of Virginia contains a non-IOC clause similar to the Federal one, and that is what your cases talk about. drlevy would be incorrect, but for the wrong reason.