Firearms Freedom Acts
A “Firearms Freedom Act” is an act of a state legislature which basically states that any manufacture, sale, or possession of firearms that occurs exclusively within the borders of the state is not subject to Federal jurisdiction. To date, such laws have been adopted by eight states, including Wyoming, and introduced in at least a dozen more.
The states that have adopted such legislation cite the Tenth Amendment as grounds.
To date there has been no litigation regarding these laws.
Enter Wyoming: (Update 2/25: this bill failed to reach the floor)
Wyoming has just introduced legislation to amend their Firearms Protection Act to include the following language:
(d) Any federal law, rule, regulation or order created or effective on or after January 1, 2013 shall be unenforceable within the borders of Wyoming if the law, rule, regulation or order attempts to:
(i) Ban or restrict ownership of a semi-automatic firearm or any magazine of a firearm; or
(ii) Require any firearm, magazine or other firearm accessory to be registered in any manner.
Expect the ATF to have kittens over this if it passes.
Reports to the contrary, technically this act does not attempt to nullify any federal law; a potentially important technicality.
Commerce Clause Jurisprudence:
For additional reading see this fine article giving a brief history of Supreme Court Commerce Clause jurisprudence.