A divided Supreme Court ruled Thursday that foreign terrorism suspects held at Guantanamo Bay have rights under the Constitution to challenge their detention in U.S. civilian courts.
The justices, in a 5-4 ruling, handed the Bush administration its third setback at the high court since 2004 over its treatment of prisoners being held indefinitely and without charges at the U.S. naval base in Cuba.
Justice Anthony Kennedy wrote the majority opinion and was joined by Justices John Paul Stevens, Stephen Breyer, David Souter and Ruth Bader Ginsburg. Dissenting were Chief Justice John Roberts, Antonin Scalia, Clarence Thomas and Samuel Alito.
"Petitioners have the constitutional privilege of habeas corpus. They are not barred from seeking the writ or invoking the Suspension Clause's protections because they have been designated as enemy combatants or because of their presence at Guantanamo," Kennedy wrote.
The Suspension Clause is a constitutional guarantee that blocks Congress from suspending habeas corpus.
"The Suspension Clause has full effect at Guantanamo. The government's argument that the Clause affords petitioners no rights because the United States does not claim sovereignty over the naval station is rejected," the opinion reads.
U.S. Attorney General Michael Mukasey said Friday the Supreme Court's decision on Guantanamo detainees won't affect military trials against enemy combatants.
Mukasey, speaking at a Group of Eight meeting of justice and home affairs ministers, said he was disappointed with the decision.
But he told reporters it won't affect military trials to be held at the U.S. naval facility at Guantanamo Bay, Cuba.
Roughly 270 men remain at the island prison, classified as enemy combatants and held on suspicion of terrorism or links to Al Qaeda and the Taliban.
Five high-profile Guantanamo detainees appeared in a military tribunal last week, where one, Ramzi Binalshibh, admitted he was guilty of helping plan the Sept. 11, 2001, terror attacks, and mastermind Khalid Sheikh Mohammed said he wanted to be put to death so he could be viewed as a martyr.
The case before the Supreme Court was brought by Lakhdar Boumediene, one of the remaining prisoners at Guantanamo Bay. He's been there since 2002.
After the court ruled in 2004, in Rasul v. Bush, that the prisoners were entitled to have access to the American court system, the government established a military tribunal process. As it stands, the prisoners can appeal adverse rulings to the D.C. Circuit Court of Appeals.
Solicitor General Paul Clement argues the process provides Boumediene "along with the other enemy combatants being held at Guantanamo Bay, [the opportunity to] enjoy more procedural protections than any other captured enemy combatants in the history of warfare."
But the detainees' lawyers contend the current law fails to protect the constitutional rights the court said their clients were entitled to receive in Rasul. They want full habeas corpus rights, a constitutional protection that forces the government to justify in an open courtroom legitimate reasons an individual needs to be behind bars.
Also known as the "Great Writ," it is a universal right that was famously suspended by Abraham Lincoln during the Civil War.
Lawyers for the detainees argued the government, through the 2006 Military Commissions Act, unconstitutionally suspended the Great Writ for their clients. They sought a single remedy: a fair and impartial hearing before a neutral decision-maker to determine if there is a reasonable basis in the law and fact for detaining them.
They have never received such a hearing, although this court ruled more than three years ago that they are entitled to one.
The government contended the Rasul decision does not cover habeas rights and that earlier court rulings make clear that foreign prisoners held outside the United States have no such right. It further argued that the military tribunals passed by Congress are an adequate substitute for what habeas seeks to protect.
Although Congress expressly chose to foreclose detainees from challenging their status via habeas, it decided that aliens detained at Guantanamo Bay as enemy combatants should receive administrative hearings before a military tribunal, subject to judicial review in the District of Columbia Circuit.
That system builds additional protections on those available even to conventional prisoners of war under the Geneva Convention, and it was designed to track the requirements for due process deemed sufficient for American citizens.
Boumediene is an Algerian native who was living in Bosnia at the time of his arrest in October 2001. He and five others are accused of plotting to blow up the American embassy in Sarajevo. They were relocated in January 2002 to Guantanamo Bay, where Boumediene remains incarcerated. He denies any involvement in plots against the United States.
This case had provided one surprising twist. In April 2007, the court decided not to consider the matter but reversed itself in June. It is believed to be the first time in 60 years that the court changed course in such a manner.
The reversal required at least five of the nine justices to grant review. Normally, only four need to agree to hear a case, and even then very few are granted arguments.
FOX News' Lee Ross and The Associated Press contributed to this report.