By Pete Williams, NBC News Justice correspondent
Not once in the history of the United States has the Supreme Court ever said what the Second Amendment means. That surprising fact is one reason why the case the justices are hearing today is likely to produce the most important ruling ever on gun rights.
The amendment itself is just 27 words long, interrupted three times by the punctuation fashionable at the time of the nation's founding: "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
To Dick Heller of Washington, DC, who wants to keep a handgun at home for personal protection, the words guarantee a personal, individual right to own a gun. His lawyers argue that the key phrase is "the right of the people to keep and bear Arms." The amendment's first words, dealing with a well regulated militia, state only one of many purposes for establishing that right, they argue, and do not limit its protections.
Heller sued after the city denied his application for a handgun permit. And though a trial judge ruled against him, finding as virtually every other court has that the Second Amendment's guarantee is limited to purposes of militias, the federal appeals court in Washington ruled 2-1 in his favor and struck down the city's handgun ban, the nation's strictest gun control law.
But the city of Washington argues that the first part of the amendment states the founders' only purpose, to protect the states from having their militias disarmed by a hostile and distant federal government.
"The amendment does not encompass having a gun for personal purposes," says Walter Dellinger, who represents the city. For that reason, the city says it did not violate the Constitution when it banned handguns in 1976, after concluding that existing laws did not adequately reduce gun violence.
The two sides each claim to find support in the history of the Bill of Rights and the writings of the founders. The city argues that the word "arms" means weapons and that the phrase "bear arms" refers to using them in a military context. "One does not bear arms against a rabbit or an intruder," Washington's legal brief argues.
But Heller's lawyers claim that the phrase was not solely a military one and that state constitutions drafted in the late 1700's guaranteed a right of citizens to "bear arms" in self defense. Besides, they say, militias were ad hoc, come-as-you-are organizations that had no central weapons stock. "In order for people to act as militias, they had to have their own weapons that they bring with them," says Alan Gura, arguing the case for Heller.
The legal showdown has generated intense interest. From Congress, 229 Republicans and 66 Democrats filed a brief supporting Heller. Vice President Dick Cheney took the highly unusual step of signing on in his capacity as President of the Senate. That put him at odds with the Bush Administration's formal position filed by the Justice Department, which argues that the amendment provides an individual right. But the government claims that the appeals court ruling is so sweeping that, if upheld, it could jeopardize federal gun laws.
A ruling that the Second Amendment guarantees an individual right to gun ownership, say gun control advocates, would instantly launch new challenges to gun restrictions nationwide. Heller's lawyer, Alan Gura, believes the impact would be more modest.
"Commonsense laws banning felons from owning guns or requiring background checks would be allowed. But it would take prohibition off the table," he says.
A contrary ruling, that gun ownership is constitutionally protected only for service in militias, would give state and local governments more authority to regulate firearm ownership, though many state constitutions would limit such restrictions.
"It would leave to the democratic process in each city and state to decide what level of regulation to have on guns," says Walter Dellinger, the city's lawyer.
A decision is expected by late June, but it's difficult to handicap how the court may rule, since the justices have never confronted the issue directly. The court's only relevant gun control case, in 1939, upheld a federal ban on sawed-off shotguns, but it did not squarely address what the Second Amendment means.