Missouri has new a law that claims to invalidate all federal gun control laws — and prohibits state and local cooperation with enforcement of those laws.
The law declares federal laws and regulations "that infringe on the people's right to keep and bear arms as guaranteed by the Second Amendment ... must be invalid in this state."
Parson, a Republican, said in a press release that the legislation "draws a line in the sand and demonstrates our commitment to reject any attempt by the federal government to circumvent the fundamental right Missourians have to keep and bear arms to protect themselves and their property."
But can a state actually invalidate a federal law?
"They can pass a law that says that there are 46 planets, they can pass a law that says that there are 16 days in the week. It doesn't make it so," says Stephen Vladeck, a professor at the University of Texas at Austin School of Law and an expert on federal courts and constitutional law. "It has no effect legally because the Constitution specifically says you can't do that."
"If I am a resident of Missouri, I am no less subject to federal gun laws today than I was yesterday," Vladeck tells NPR.
The Constitution says federal law is supreme over state law
The U.S. Constitution's Supremacy Clause essentially says federal law is supreme over state law. And the preemption doctrine means that "valid federal law will always displace a state law, even a state constitutional provision that is inconsistent with that federal law," Vladeck says.
He notes that after the Affordable Care Act was enacted, some states passed laws that said the ACA wouldn't apply in those states. But that hasn't stopped the ACA from being the law of the land in every state.
So, what sort of federal gun laws are there? There are limits on what kinds of guns you can sell across state lines, and limits on what kind of guns and accessories can be sold in the first place. There are federal background check requirements. One provision bans the possession of firearms by individuals convicted of a misdemeanor crime of domestic violence. And there are laws governing the process and substance of gun sales, Vladeck says.
The new law doesn't change the liability of people in Missouri or exempt them from federal laws. So if you're a Missouri gun shop owner, you're still required to uphold federal background check requirements and other federal laws, even if the governor suggests otherwise.
Vladeck views Missouri's new law as symbolic public relations stunt. But he says it's symbolism that can be harmful: "You run the risk that the state officials are actually sending a message to their constituents that is just incorrect, and that is exposing them to legal liability that they may not otherwise realize."
"A Missouri gun store that thinks all of a sudden it can stop complying with federal law is going to receive a pretty unpleasant visit from federal authorities," Vladeck says.
States can decide not to help federal law enforcement
While states can't invalidate federal law, they can decide the extent to which they assist federal law enforcement.
"Under the 10th Amendment, states do have the right to withhold the use of their resources to enforce federal laws," says Allison Anderman, senior counsel at Giffords Law Center to Prevent Gun Violence.
"We're just simply saying we're not going to lift a finger to enforce their rules," Missouri state Sen. Eric Burlison, a Republican, said of the bill last month, according to The Kansas City (Mo.) Star.
In addition to claiming to invalidate federal gun laws, Missouri's new law prohibits state and local cooperation with enforcement of those laws. Agencies whose officers knowingly enforce federal gun laws could be hit with fines of $50,000 for each violating officer.
State and local officers are not usually tasked with going out and enforcing federal law, Vladeck says – usually it happens in an ancillary fashion: "If they're conducting a search of a home because of probable cause of a state crime, they might also find evidence of a federal crime that they'll refer to federal authorities."
Whether local law enforcement in Missouri will do that when it comes to guns is now in question.
The Department of Justice sent a letter on Wednesday night to Parson and Missouri Attorney General Eric Schmitt, warning that the state's law could damage the working relationship between local and federal authorities, The Associated Press reported. Acting Assistant Attorney General Brian Boynton asked Parson and Schmitt to clarify the law and how it would work by Friday.
A spokesperson for the Justice Department confirmed the accuracy of the AP's report. NPR has not viewed the letter.
NPR asked the Bureau of Alcohol, Tobacco, Firearms and Explosives whether the statute would have an impact on its enforcement in the state, but an ATF spokesperson said the agency does not comment on local or state firearms law.
It could have a chilling effect on law enforcement
The law could have a chilling effect on law enforcement officers' actions when it comes to guns, even if its provisions are unconstitutional and confusing, Anderman says.
"There is a tremendous amount of ambiguity in this bill as to what would constitute a violation, and that may inhibit law enforcement from taking action that is needed to protect the community," she tells NPR.
Say an officer encounters someone who has a felony conviction and is in possession of a firearm?
"They may not refer that case to federal law enforcement out of fear that they would be liable for a $50,000 fine. And that in turn can result in lack of prosecution of a law that is intended to keep guns out of the hands of people who have committed society's most serious crimes," Anderman says.
The state is not alone in considering this kind of legislation. Arkansas Gov. Asa Hutchinson said in April he would sign a similar bill approved by the Legislature there.
Other states are considering legislation to nullify federal gun laws. But Missouri's law, Anderman says, will have real-life consequences — whether or not any law enforcement officers are actually prosecuted and fined.
"How many officers have failed to take some action that they might have otherwise taken because of this law? We will likely never know the answer," she says, "but it's the deterrent effect that is so concerning."