A Missouri gun bill  will test so-called nullification theories.
The Republican-controlled state legislature is expected to easily pass a bill which would nullify all federal gun laws in Missouri. Under the proposed law, a Missouri citizen arrested under federal gun statutes even would be entitled to sue the arresting law enforcement officer.
The gun bill is being touted as the most extensive states’ rights action in the country in decades. The nullification movement is gaining traction around the United States as defiance against what many see as over-reaching federal power and as Second Amendment  infringement increases. The Missouri GOP reportedly believes linking gun rights to nullification actions works well.
“It’s probably one of the best states’ rights issues the country’s got going right now,” said state Republican Party director of communications Matt Wills .
Under nullification theory, individual states have the right to invalidate federal laws because individual states preceded the Union and formed the U.S. under a “compact” or agreement. The Declaration of Independence, supporters say, speaks of “free and independent states.” 
Missouri Gov. Jay Nixon  deemed the nullification bill unconstitutional last month and vetoed it. The state legislature will meet again on Sept. 11, and will attempt to override the Democratic governor’s veto. Although a host of legal experts believe the court system will ultimately thwart the Missouri gun bill, almost all Republicans and about a dozen Democrats are expected to vote for the veto override.
Nixon noted in his veto that he believes the bill violates Article VI, Clause 2, of the US Constitution. That section of the document drafted by our Founding Fathers is often referred to as the Supremacy Clause. The Missouri Governor stated in his bill response letter that he feels the Supremacy Clause  was written to “provide a mechanism to enforce federal acts and to resolve discord between state and federal laws which touch upon the same subject.” Nixon went on to say that he believes the Supremacy Clause gives precedence to federal laws over state laws.
The Supremacy Clause reads, in part:
“This Constitution, and the laws of the United States which shall be made in pursuance thereof; and all treaties made, or which shall be made, under the authority of the United States, shall be the supreme law of the land; and the judges in every state shall be bound thereby, anything in the Constitution or laws of any State to the contrary notwithstanding.”
Richard G. Callahan, Eastern District of Missouri United States attorney, recently stated that federal, state, and local law enforcement operations would be jeopardized if the federal gun statute nullification bill passes. Callahan also said that the law would essentially make criminals out of police officers.
Missouri State Representative Doug Funderburk, a Republican, wrote the gun nullification bill and fully expects it to become law.
Libertarian and Cato Institute board of directors chairman Robert A. Levy feels the Missouri gun nullification bill crosses the line.
“With the exception of a few really radical self-proclaimed Constitutional authorities, state nullification of federal law is not on the radar scope,” Levy said.
Should the Missouri gun  bill make it to the state Senate, it will likely pass there, as well. According to The New York Times, all Republicans and two Democrats inside that governing body are expected to vote in favor of the bill. To date, the National Rifle Association has not weighed in on the gun nullification legislation. In the past, the NRA has given Nixon credit for inking pro-gun bills. Nullification bills have had some success in the past and have been used by states to enact, for instance, marijuana legalization.