US v. Hosford: Hosford sold several firearms to an undercover cop. Hosford did not have a federal firearms license. Therefore, he was charged with multiple counts of unlicensed firearms dealing and conspiracy (a confederate bought the guns at gun shows that Hosford then sold). He entered a guilty plea, preserving the right to appeal the district court's denial of his motion to dismiss the charges as violating the Second Amendment, due process under the Fifth Amendment, and he Commerce Clause.
On appeal, the Fourth Circuit affirmed the denial and Hosford's convictions. On the Second Amendment challenge, it held that Hosford's facial challenge was to the "type of regulation deemed 'presumptively lawful' in Heller and "thus facially constitutional." On the as applied Second Amendment challenge, the court applied intermediate scrutiny (after assuming, arguendo, that the law burdens "conduct protected by the Second Amendment") and concluded that the important Government interests involved in regulating the commercial sale of firearms satisfied that burden. Next, the court held that the unlicensed firearm statute was not unconstitutionally vague, even though it did not clarify whether someone is a "dealer" versus a "collector." The statute "clearly gave notice to Hosford that he ought not to regularly sell firearms that he only purchased and resold for profit." Finally, the court held (joining all the other circuits to consider the issue) that the regulation of commercial firearms transactions falls within Congress's power under the Commerce Clause.