President-elect Donald Trump could end or at least prohibit the enforcement of numerous gun controls in California, Illinois, New York, and New Jersey when he assumes office.

He would simply need to sign national reciprocity legislation as soon as it reaches his desk.

Trump has already made his support for national reciprocity clear–he says the concealed carry license of one state should be recognized in every state. And if he were to sign a bill making national reciprocity the law of the land, it would automatically override the limits on concealed carry that exist in states like CA, IL, NY, and NJ, and would allow a concealed permit holder from Oklahoma to legally carry his gun in California for self-defense.

It would allow a concealed permit holder in Wisconsin to carry a gun in Chicago for self-defense–something currently banned by Illinois law–and it would allow a concealed permit from Texas to legally carry a gun in New York for self-defense. Likewise, a concealed carry permit holder from Colorado or Idaho would be able to carry a gun for self-defense in New Jersey.

Seen in this light, national reciprocity would really serve as a preemption law; a law that would bar states from rejecting a license that had been granted federal recognition. It is very similar to the way things work with a driver’s license.

Trump first made his support for national reciprocity clear when he released a position paper on his gun policy in September 2015. In that release he wrote:

The right of self-defense doesn’t stop at the end of your driveway. That’s why I have a concealed carry permit and why tens of millions of Americans do too. That permit should be valid in all 50 states. A driver’s license works in every state, so it’s common sense that a concealed carry permit should work in every state. If we can do that for driving – which is a privilege, not a right – then surely we can do that for concealed carry, which is a right, not a privilege.

National reciprocity in a crucial step toward ensuring Americans with concealed carry permits have the ability to exercise their Second Amendment rights regardless of their geographic location. And it is something which President Trump will be able to accomplish with the swipe of a pen, if the Republican-led Congress simply hunkers down and gets the legislation through to his desk.

AWR Hawkins is the Second Amendment columnist for Breitbart News and host of “Bullets with AWR Hawkins,” a Breitbart News podcast. He is also the political analyst for Armed American Radio. Follow him on Twitter: @AWRHawkins. Reach him directly at awrhawkins@breitbart.com.