The government's lawyers argued that 18-to-20-year-olds are not part of "the people" whose "right to keep and bear arms" is guaranteed by the Second Amendment. They cited "the common law's recognition of 21 years as the date of legal maturity at the time of the founding" and "the fact that legislatures have long established minimum age requirements for various activities."
As Judge Edith Jones notes in the 5th Circuit's opinion, however, "there are no age or maturity restrictions in the plain text of the Amendment, as there are in other constitutional provisions," which "suggests that the Second Amendment lacks a minimum age requirement." She also observes that "the right of the people peaceably to assemble" (protected by the First Amendment), "the right of the people" to be secure from "unreasonable searches and seizures" (protected by the Fourth Amendment), and the unspecified rights "retained by the people" under the Ninth Amendment "undoubtedly protect eighteen-to-twenty-year-olds as much as twenty-one-year-olds."

The 5th Circuit says the federal ban on handgun sales to young adults is unconstitutional
The federal ban on handgun sales to adults younger than 21 violates the Second Amendment, the U.S. Court of Appeals for the 5th Circuit ruled today. That
