Conservative efforts to stop the enforcement of gun laws.

http://www.huffingtonpost.com/2015/02/26/federal-gun-laws_n_6754416.html

Conservative lawmakers in at least 11 states are pushing legislation that would prevent state law enforcement from enforcing some or all federal gun restrictions. Proponents of these bills are emboldened by the success of marijuana legalization at the state level and claim that federal law enforcement is stretched too thin to stop them.
Right now, there are a number of federal laws restricting various kinds of gun use. For example, felons, fugitives, people convicted of domestic abuse misdemeanors and people subject to certain domestic restraining orders are restricted from buying guns under federal law. And no civilians are allowed to buy newly manufactured machine guns.
In Montana, the state House passed legislation earlier this month that would prohibit the enforcement of any potential federal ban or restriction on firearms and magazines. If a Montana cop did enforce such a federal law, it would be considered theft of public money. The Montana bill says that state employees are still allowed to enforce some federal laws -- for example, the ban on machine guns. But most states that have introduced this type of legislation have used broader language.