Although the Second Amendment is among the best-known provisions of the Constitution, it has had remarkably little effect on the law.

Gun owners, led by the National Rifle Association, have spotlighted the amendment's reference to "the right of the people to keep and bear Arms" in waging political battles against efforts to limit the availability of weapons.

But in the Supreme Court's only major ruling that interpreted the amendment, it focused on the measure's opening words, which speak of "a well-regulated Militia" being "necessary to the security of a free State."