The Bureau of Alcohol, Tobacco, Firearms, and Explosives (BATFE) insists you lose your Second Amendment rights if you let your state know you might want to use marijuana medicinally. According to a memo the BATFE sent to licensed gun dealers in September, possessing a state medical marijuana card triggers a provision of federal law that bars anyone "who is an unlawful user of or addicted to any controlled substance" from owning guns or ammunition.
Rowan Wilson, a Nevada medical technician, is challenging that policy via a federal lawsuit filed in October. She obtained a Nevada medical marijuana card in 2010 because she was considering using marijuana to relieve pain from menstrual cramps. In September, a gun dealer who knew her personally and knew she possessed the card refused to sell her a gun because of the BATFE's policy.
According to her suit, "Ms. Wilson has never been charged with or convicted of any drug-related offense, or any criminal offense.…Indeed, no evidence exists that Ms. Wilson has ever been 'an unlawful user of, or addicted to, marijuana.'" UCLA law professor Eugene Volokh agrees that "barring everyone from selling a weapon to her because she has a card denies her her Second Amendment rights without actually showing she is an illegal user." But Volokh isn't sure the courts will agree. He suspects the best relief she can expect is "a declaratory judgment that she is entitled to get a gun so long as there is no other evidence she is a marijuana user."