At oral arguments on Tuesday, the nine justices will, for the first time in nearly 70 years, try to interpret whether the Second Amendment provides an individual right to own firearms or only the right of a state to keep a militia without federal interference.
The law at issue before the court is a handgun ban in Washington, D.C. The ban, considered the most restrictive in any major American city, also requires rifles and shotguns to be kept disassembled or equipped with a trigger lock, which critics of the measure say makes them less useful for self-defense during home invasions. The law is being challenged by a security guard, Dick Heller, who wants to be able to keep a handgun at home.
In most states, law-abiding adults face few impediments to gun ownership. But in some metropolitan areas, including New York, licensing requirements are strict. Such municipal laws would come under scrutiny if the Supreme Court struck down the Washington ban as violating the Second Amendment.
"I can guarantee that if we win this, New York's laws will be challenged," a lawyer who is representing Mr. Heller, Robert Levy of the Cato Institute, said.
Mr. Levy, who has financed Mr. Heller's suit, said he currently has no plan to bring a similar suit challenging New York City's gun regulations. New York does not have an outright ban on handguns, but the city gives the police department discretion in deciding to grant handgun permits, preventing many law-abiding citizens from keeping one at home. For advocates of gun rights, a Supreme Court decision that says the Second Amendment provides an individual right to keep guns does not necessarily mean victory. Legal experts say the federal high court could decide that even if such a right under the Second Amendment does exist, it is tempered by the government's interest in regulations meant to minimize violence. Subsequent courts could decide that restrictions such as Washington's or New York's, as well as federal laws banning certain types of firearms, are all reasonable, even in light of an individual right under the Second Amendment.
Whether courts will give more deference to state and municipal gun control laws than to a federal gun control law, such as the district's handgun ban, is also an open question.
District of Columbia v. Heller has attracted many friend of the court briefs, including some from New York officials. Attorney General Cuomo and New York City's law department are backing Washington's handgun ban, as are the district attorneys of Brooklyn, the Bronx, Manhattan, and Queens.
Neither Senator Clinton nor Senator Obama, both candidates for the Democratic presidential nomination, signed on to any briefs. Senator McCain, along with 54 other senators, has asked the Supreme Court to affirm a lower court ruling that struck down the Washington ban.