George Leef’s latest Forbes column delves into recent attacks on constitutionally protected gun rights.

Earlier this year, Justice Clarence Thomas caused a mild sensation among Court watchers when he asked his first question from the bench in a decade. His question to the government’s counsel was why should it be so easy for a citizen to be deprived of his or her rights under the Second Amendment. (I wrote about the incident and the underlying case here.)

That question applies with equal force in a case where state officials have decided to deny gun permits to individuals who have been issued cards enabling them to purchase medical marijuana. Why should the fact that a person could purchase marijuana for medical purposes be grounds for declaring him ineligible to own a gun?

Here are the facts.

A woman who is a Nevada resident, Rowan Wilson, sought to purchase a gun from a firearms store in the town of Mound House in 2011. The owner of the shop (Fred Hauser) however, refused to sell to her because he was aware that she had recently obtained a medical marijuana registry card from the Nevada Department of Health and Human Services.

The reason why that mattered to him was that gun shop owners had received a letter from the federal Bureau of Alcohol, Tobacco, Firearms, and Explosives (BATF) stating that any person who uses marijuana for medical purposes qualifies as an “unlawful user of a controlled substance” and is therefore forbidden to purchase a firearm under federal criminal law.

Therefore, if Hauser had sold Ms. Wilson a firearm, he would have committed a felony since he had “reasonable cause to believe” that she was forbidden by statute to purchase a gun. Much better to lose a sale than to go to jail.

Wilson subsequently filed a lawsuit in federal court arguing that the prohibition against selling firearms to individuals who have been authorized to use medical marijuana is a violation of the Second Amendment. In March of 2014, the court ruled against her. …