Another Missouri state legislator, Rep. Casey Guernsey, introduced a similar bill that "specifies that it is unlawful for any officer or employee of the state or any political subdivision, or any licensed federal firearms dealer to enforce, or attempt to enforce, any federal law relating to a personal firearm, firearm accessory, or ammunition that is owned or manufactured in this state and remains exclusively within the boundaries of the state," according to Guernsey's legislative aide Ryan Clearwater.
Lawmakers in Tennessee laid out similar legislation. State Rep. Jeremy Faison and Sen. Frank Nicely proposed a bill that would make it illegal for any "public funds" of the state to be "allocated to the "implementation, regulation or enforcement of any federal law, executive order, rule or regulation" that is passed and "adversely affects a United States citizen's ability to lawfully possess or carry firearms in this state."
Faison also put out a statement saying while he "appreciates" some of the president's plans like "additional school resource officers, training for schools, churches, and higher education," as well as "being tougher on gun crimes," he disagrees with aspects of the proposal such as the "vague" term "military assault weapons" and private sales needing background checks.
"10 years of an assault weapons ban did nothing to stop shooting crimes. How will it work now?" Faison asked in a statement.
In Wyoming, state Rep. Kendell Kroeker was joined by several other state legislators in proposing a bill that reads "any federal law which attempts to ban a semi-automatic firearm or to limit the size of a magazine of a firearm or other limitation on firearms in this state shall be unenforceable in Wyoming."
Like other states, the bill would make it a felony for a federal employee to enforce federal legislation on a firearm or ammunition "owned or manufactured commercially or privately in Wyoming" that remains in the state.
And it's not just state legislators. A sheriff in Oregon, Tim Mueller of Linn County, wrote a letter to Vice President Joe Biden on Monday which he posted on his Facebook page, telling Biden, "We must not allow, nor shall we tolerate, the actions of criminals no matter how heinous the crimes to prompt politicians to enact laws that will infringe upon the liberties of responsible citizens who have broken no laws."
"Any federal regulation enacted by Congress or by executive order of the President offending the constitutional rights of my citizens shall not be enforced by me or my deputies, nor will I permit the enforcement of any constitutional regulations or orders by federal officers within the borders of Linn County Oregon," Mueller wrote in the letter.
Another sheriff in Kentucky, Denny Peyman of Jackson County, told The Lexington Herald-Leader that he too would not enforce any laws he considers unconstitutional, saying he has "a team of attorneys to step up with me if necessary to be sure the Second Amendment is upheld," adding that he considers it "a moral obligation."
Even before the Dec. 14 Sandy Hook school shooting that left 20 first graders and six educators dead, eight states had adopted similar laws that would exempt guns made in those states from federal regulations as long as the firearms remain in those states.
ABC News' Whitney Lloyd contributed to this report.