Did the district court deny Mr. Cox his due process right to present a defense when it precluded Mr. Cox from arguing to the jury that his reliance on the Kansas Second Amendment Protection Act could be considered an affirmative defense?

QUESTIONS PRESENTED Shane Cox owned an army surplus store in Chanute, Kansas. The store sold the usual stock (duffle bags, peppery spray, stun guns, knives), but not firearms, as Mr. Cox did not have a federal firearms license. In 2013, however, the Kansas legislature passed, and the governor signed, the Kansas Second Amendment Protection Act (codified at KSA § 50-1201 et seq.). The Act generally exempts all firearms or firearm accessories within Kansas from any federal law or regulation, including any federal registration program. With this law on the books, Mr. Cox made a short-barreled rifle for himself. He also made silencers and sold them in his store in a glass case alongside a copy of the Kansas Act. But the federal government prosecuted him anyway under the National Firearms Act, 26 U.S.C. § 5801 et seq., and a jury convicted him of possessing the unregistered short-barreled rifle and an unregistered silencer, as well as transferring unregistered silencers. The jury did so only after the district court instructed it that Mr. Cox’s reliance on the Kansas Act was not an affirmative defense. The Tenth Circuit affirmed, and also held that the Second Amendment does not protect silencers or short-barreled rifles. The questions presented are: I. Did the district court deny Mr. Cox his due process right to present a defense when it precluded Mr. Cox from arguing to the jury that his reliance on the Kansas Second Amendment Protection Act could be considered an affirmative defense. II. Are short-barreled rifles and silencers protected by the Second Amendment. i