The court is undertaking a fresh review of the Bush administration's aggressive use of preventive detention for suspected terrorists. The administration asserts that the president has the authority to order the military to detain anyone suspected of being an al-Qaida member.
The administration's policy is being challenged by Ali al-Marri, a Qatar native who was seized in the United States and is the only enemy combatant currently being held on U.S. soil. The government says al-Marri is an al-Qaida sleeper agent.
Al-Marri, represented by the American Civil Liberties Union, says he cannot be imprisoned without charge or trial. He was arrested in Peoria, Ill.
Al-Marri has been held in virtual isolation in a Navy brig near Charleston, S.C., for nearly 5 1/2 years.
The 4th U.S. Circuit Court of Appeals in Richmond, Va., said in a split decision that the president has such power, but that al-Marri must be given the chance to persuade a federal judge that he is not an enemy combatant.
The administration argued that al-Marri's case should first go to federal district court in South Carolina, instead of to the Supreme Court.
Al-Marri said that the case was of such constitutional importance that it should be heard by the high court now -- and the justices apparently agreed.
Jonathan Hafetz, al-Marri's ACLU lawyer, said he was gratified by the court's action. "The President's claim that he can seize people living in the United States and imprison them for life without trial represents one of the most dangerous exercises of executive power possible," Hafetz said.
The case will not be argued before March, meaning that President-elect Barack Obama will be in the White House and decisions about al-Marri will be made by him.
During the presidential campaign, Obama repeatedly criticized President George W. Bush for being too aggressive in asserting executive authority.
Brooke Anderson, chief national security spokeswoman for the Obama transition team, declined to comment on the case. "President-elect Obama will make decisions about how to handle detainees as president when his full national security and legal teams are in place," she said.
It is rare for an incoming administration to reverse course on a case before the high court, although it does happen.
The new administration has options if it wishes to avert a Supreme Court hearing.
It could send al-Marri home to Qatar or transfer him back to civilian court to face criminal charges. The government followed the latter path in the case of U.S. citizen Jose Padilla rather than have the high court take up the matter. Padilla, who was arrested in Chicago and held in the same brig as al-Marri, was convicted in a criminal trial in federal court in Miami.
Obama also is weighing what to do with the roughly 250 foreigners who are being held at the U.S. naval base at Guantanamo Bay, Cuba. The court has ruled that those men must be able to argue for their freedom before a federal judge, but it has not questioned the authority to seize and hold them.
Al-Marri arrived in the U.S. with his wife and five children on Sept. 10, 2001 -- one day before the terrorist attacks in New York and Washington. He entered the country on a student visa seeking a master's degree in computer science from Bradley University, a small private school in Peoria, Ill.
He was arrested three months later as part of the FBI's investigation of the Sept. 11 attacks. Prosecutors indicted him on charges of credit card fraud and lying to the FBI, not terror charges.
But in June 2003, Bush said al-Marri had vital information about terror plots, declared him an enemy combatant and ordered him transferred to military custody.
The government says al-Marri trained in al-Qaida camps and met with Osama bin Laden and Sept. 11 mastermind Khalid Sheikh Mohammed. His laptop was filled with information about poisons, coded e-mail messages and lectures by bin Laden and others on the importance of martyrdom, the government says.
Civil liberties groups were joined by former Attorney General Janet Reno, former FBI Director William Sessions, former generals and other ex-government officials in urging the court to review the case.
They said the justices should overturn the appeals court ruling backing the president's authority to detain terrorism suspects in the U.S. without charges.
The case is al-Marri v. Pucciarelli, 08-368.