Despite mountains of scholarly research, enough books to fill a library shelf and decades of political battles about gun control, the Supreme Court will have an opportunity this week that is almost unique for a modern court when it examines whether the District's handgun ban violates the Second Amendment.

The nine justices, none of whom has ever ruled directly on the amendment's meaning, will consider a part of the Bill of Rights that has existed without a definitive interpretation for more than 200 years.

"This may be one of the only cases in our lifetime when the Supreme Court is going to be interpreting the meaning of an important provision of the Constitution unencumbered by precedent,'' said Randy E. Barnett, a constitutional scholar at the Georgetown University Law Center. "And that's why there's so much discussion on the original meaning of the Second Amendment.''

The outcome could roil the 2008 political campaigns, send a national message about what kinds of gun control are constitutional and finally settle the question of whether the 27-word amendment, with its odd structure and antiquated punctuation, provides an individual right to gun ownership or simply pertains to militia service.

"The case has been structured so that they have to confront the threshold question," said Robert A. Levy, the wealthy libertarian lawyer who has spent five years and his own money to bring District of Columbia v. Heller to the Supreme Court. "I think they have to come to grips with that."

The stakes are obviously high for the District, which passed the nation's strictest gun-control law in 1976, just after residents were granted the authority to govern themselves. It virtually bans the private possession of handguns, and requires that rifles and shotguns in the home be kept unloaded and disassembled or outfitted with a trigger lock.

The law's challengers -- security guard Dick Anthony Heller is the named party in the suit -- say the measure has been an abysmal failure at cutting crime or stanching the city's homicide rate, and a success only in depriving the law-abiding of a ready weapon for protection. The District contends that banning handguns is a logical decision in an urban setting, where more guns would result in more killings.

The city's lawyers argue that the Second Amendment does not provide an individual right and that, even if it does, the amendment is not implicated by legislation that concerns only the District of Columbia.

Bold breaks The case could be a revealing test of the court headed by Chief Justice John G. Roberts Jr. Roberts came to the bench saying justices should decide cases as narrowly as possible, but last year he was part of a slim majority that made bold breaks with the court's jurisprudence in cases both recent and old, on issues such as school integration and abortion.

Clues to the justices' interpretations of the Second Amendment are scant and cryptic, and Roberts said during his 2005 confirmation hearings that the last time the court considered the issue -- in 1939 -- it "sidestepped" the fundamental questions.

That is part of the reason that the outcome -- not expected until near the end of the court's term in late June -- will be so intriguing, said Suzanna Sherry, a law professor at Vanderbilt University.

"It is very rare that the justices write on a clean slate," she said. "In some ways, it gives them great freedom."

Levy and lawyers Alan Gura and Clark Neily were able to persuade the U.S. Court of Appeals for the District of Columbia Circuit last year to do what no other federal appeals court had ever done: strike down a local gun-control ordinance on Second Amendment grounds.

The amendment says that "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,'' and all but one of the circuits that had considered the issue previously had interpreted it as providing a gun-ownership right related only to military service.

But Senior Judge Laurence H. Silberman, a conservative icon, wrote for a 2 to 1 panel that the amendment provides an individual right just as other provisions of the Bill of Rights do. And because handguns fall under the definition of "arms," he wrote, the District may not ban them.

The Supreme Court's endorsement of an individual right would be a monumental change in federal jurisprudence, but perhaps not surprising. Even a small but growing group of liberal constitutional scholars -- "against my political instincts," in the words of Harvard law professor Laurence H. Tribe -- have endorsed the individual-right view.

But even fundamental rights are subject to government restrictions, and whether the justices are ready to decide on the reasonableness of the District's ban could be the crucial question of the case.

The city received an unlikely lifeline from the Bush administration, which told the court that the amendment provides an individual right but that the appeals court erred in deciding that the District's ban was automatically unconstitutional.

"If adopted by this court," Solicitor General Paul D. Clement wrote in the government's brief, "such an analysis could cast doubt on the constitutionality of existing federal legislation prohibiting the possession of certain firearms, including machineguns."

Clement said that the District's law may well be unconstitutional, but that the case should be returned to lower courts for "application of a proper standard of review" and to permit "Second Amendment doctrine to develop in an incremental and prudent fashion."

Gun rights supporters were furious about the government's position, and Vice President Cheney went so far as to join a friend-of-the-court brief that specifically rejects the administration's view. Levy said returning the case to lower courts would be a "death knell," and his team has urged the court to apply "strict scrutiny" to any government action that would restrict gun ownership.

'Take prohibition off the table'

Said Gura: "What we want to do is take prohibition off the table."

The case is complicated by the District's secondary argument that the Second Amendment is not implicated by legislation that applies only to the District of Columbia.

The challengers have received a broad array of political support, signs of the strength of the gun rights movement: More than 31 states and a majority of the House and Senate have signed friend-of-the-court briefs.

Among the presidential candidates, Republican Sen. John McCain signed on, while Democratic Sens. Barack Obama and Hillary Rodham Clinton did not. Both Democrats have looked for a middle ground, saying they believe the Second Amendment preserves an individual right, but one that is subject to government restrictions.

That position would seem popular. A Washington Post poll shows that 72 percent of the public believes the Constitution provides an individual right, but respondents were evenly split on whether it is more important to protect the rights of Americans to own guns or to control gun ownership.

Nearly 60 percent said they would support the kind of law in question.

But nationally, it is hard to find many laws as restrictive as the one in the District, partly because of the gun rights lobby's vigilance. More than 40 state constitutions have gun ownership guarantees. Maryland's is one of the few that does not.

As a result, it is difficult to know what gun-control legislation across the country would be at risk even if the Supreme Court upheld the D.C. Circuit's decision.

Levy said the next targets will be handgun laws in Chicago and New York City, although the court has never held that the Second Amendment is applicable to states. And one legal theory is that the provision is a restriction only against the federal government.

Both sides agree that the court's decision could send a powerful message beyond the District.

Tribe, whose support of the individual right is often cited by gun rights supporters, wrote an article in the Wall Street Journal recently that said the District's law could still be upheld and urged the court to decide the case narrowly.

But he acknowledged in an interview that the justices might "jump at the opportunity" to write broadly when they finally have a chance to put their mark "on a part of the Constitution that isn't already paved over with layer upon layer of judicial precedent."

Polling director Jon Cohen and researcher Madonna Lebling contributed to this report.

www.msnbc.msn.com/id/23656329/print/1/displaymode/1098