WASHINGTON — The Supreme Court gets to write on a blank slate when it takes up the meaning of the Second Amendment “right to keep and bear arms” and the District of Columbia’s ban on handguns.

The nine justices have said almost nothing about gun rights, and their predecessors have likewise given no definitive answer to whether the Constitution protects an individual’s right to own guns or whether that right is somehow tied to service in a state militia.

The case that will be argued tomorrow is among the most closely watched of the term, drawing 68 briefs from outside groups. Most of those support an individual’s right to own a gun.

“This may be one of the only cases in our lifetime when the Supreme Court is going to interpret an important provision of our Constitution unencumbered by precedent,” a Georgetown University law professor, Randy Barnett, said.

Even if they determine there is an individual right, the justices still will have to decide whether the capital’s 32-year-old handgun ban can stand and how to evaluate other gun control laws. This issue has caused division within the Bush administration, with Vice President Cheney taking a harder line than the administration’s official position at the court.

The local Washington government argues that its law should be allowed to remain in force whether or not the amendment applies to individuals, although it reads the amendment as intended to allow states to have armed forces.

The City Council that adopted the ban said it was justified because “handguns have no legitimate use in the purely urban environment of the District of Columbia.”

An armed security guard, Dick Anthony Heller, 65, sued the District after it rejected his application to keep a handgun at his home — about a mile from the court — for protection. His lawyers say the amendment plainly protects an individual’s right.

The 27 words and three enigmatic commas of the Second Amendment have been analyzed again and again by legal scholars, but hardly at all by the Supreme Court.

The amendment reads: “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.”

The last Supreme Court ruling on the topic came in 1939 in U.S. v. Miller, which involved a sawed-off shotgun. Constitutional scholars disagree over what that case means but agree it did not squarely answer the question of individual versus collective rights.

Chief Justice Roberts said at his confirmation hearing that the correct reading of the Second Amendment was “still very much an open issue.”

Mr. Heller lost his suit in U.S. District Court in Washington. By a 2-1 vote, a panel of the U.S. Circuit Court of Appeals for the District of Columbia struck down the handgun ban. Notably, it was the first appeals court to strike down a gun control law on the basis of an individual’s Second Amendment rights.

In 2001, Attorney General Ashcroft reversed long-standing Justice Department policy when he asserted that the Second Amendment protects individuals’ rights. The administration’s brief in this case holds to that view.

But the Solicitor General, Paul Clement, told the court that reasonable restrictions should be allowed and warns that federal laws restricting sales of machine guns and barring felons from owning guns, among others, could be threatened under the appeals court ruling. Mr. Clement wants the court to send the case back to lower courts without deciding whether the handgun ban is reasonable.

Mr. Clement’s brief was harshly criticized by supporters of gun rights. Mr. Cheney joined majorities in both the House and Senate in signing a brief that says a handgun ban is clearly unreasonable. Experts on the court could recall no other case in which a vice president took a public position disagreeing with the administration he serves.

Mr. Barnett is among those on both sides of the issue who believe the practical effect of the court’s ruling will be limited.

Forty-four state constitutions contain some form of gun rights, which are not affected by the court’s consideration of Washington’s restrictions.

“There is almost no other enacted gun law that would be threatened by this case,” Mr. Barnett said.

The case is Heller v. District of Columbia, 07-290.