The United States Constitution, Article 1, Sections 9 and 10 state the following: Article 1, Section 9 - No bill of attainder or ex post facto Law shall be passed. Article 1, Section 10 - No state shall enter into any treaty, alliance, or confederation; grant letters of marque and reprisal; coin money; emit bills of credit; make anything but gold and silver coin a tender in payment of debts; pass any bill of attainder, ex post facto law, or law impairing the obligation of contracts, or grant any title of nobility. Given the proscriptions stated above, how does New York expect to retroactively ban any weapons, magazines, etc. which are legal the day before the laws take effect? Congress passed the AWB of 1994, but guns, magazines, etc., produced prior to the law's effective date were legal as per Article 1, Section 9. How does state law usurp existing Federal laws?