Absent action by Congress, all that remains are 23 executive orders Obama announced that apply only to the federal government, not local or state law enforcement.
In Mississippi, Gov. Phil Bryant, a Republican, urged the Legislature to make it illegal to enforce any executive order that violates the Constitution.
"If someone kicks open my door and they're entering my home, I'd like as many bullets as I could to protect my children," Bryant said. "And what we're doing now is saying, 'We're standing against the federal government taking away our civil liberties.' "
Tennessee Republican State Rep. Joe Carr wants to make it a state crime for federal agents to enforce any ban on firearms or ammunition. He instead called for more armed guards at schools.
Legislative proposals to preempt federal gun restrictions also have arisen in Wyoming, Utah, and Alaska.
A Wyoming bill specifies that any federal limitation on guns would be unenforceable. It also would make it a state felony for federal agents to try to enforce restrictions.
In Utah, some Republicans are preparing legislation to exempt the state from federal gun laws - and fine any federal agents who try to seize guns. A bill in the Alaska House would make it a misdemeanor for a federal agent to enforce new restrictions on gun ownership.
While such proposals are eye-catching, they likely could not be implemented.
"The legislature can pass anything it wants," said Sam Kamin, a constitutional law professor at the University of Denver. "The Supremacy Clause of the Constitution makes that clearly unconstitutional. Where there's a conflict between state and federal law, the federal government is supreme."