The U.S. Supreme Court appeared deeply divided Wednesday over just how much due process Guantanamo Bay detainees deserve in challenging their imprisonment – and how much they already have.

Twice before, related issues have gone before the high court, and twice the court has ruled in favor of the detainees. But on Wednesday, that trend seemed in jeopardy, as justices weighed the impact of a law passed by Congress last year that stripped U.S. courts of jurisdiction to hear habeas corpus appeals from detainees and established a limited appeal process.

It also appeared possible that the court will return the case to lower courts for a fuller examination of the adequacy of the new appeals process as a substitute for traditional habeas corpus review.

But neither side wants further delay. The Bush administration hopes to proceed with military tribunals that have been revised several times and ensnared in litigation, and the detainees’ representatives seek an end to nearly six years of unreviewed imprisonment at the U.S. base in Guantanamo Bay, Cuba.

“The political branch has spoken,” declared Solicitor General Paul Clement, who argued that the appeals process spelled out by Congress in the Military Commissions Act of 2006 gives detainees substantial appeal rights that amount to a “remarkable liberalization of the writ” of habeas corpus, not a retrenchment.

But former Solicitor General Seth Waxman, representing 37 Guantanamo detainees, argued just as forcefully that in the nearly six years they have been confined, the detainees have never been able to challenge their detentions before a neutral decision-maker, and “they have no prospect of getting that opportunity.” Waxman also said, “The time for experimentation is over.”

The dramatic argument in Boumediene v. Bush spilled beyond the allotted one hour, as both advocates engaged in unusually heated debates with justices who are likely to vote against them. More than 70 people spent a cold night in line outside the court to wait for seats, and among the spectators were Sens. Edward Kennedy, D-Mass., and Lindsey Graham, R-N.C.

Like fighters shaking hands before entering the ring, Waxman and Clement embraced before the arguments began. The current and former solicitors general treated the justices and spectators to one of the best-argued cases in recent memory, with neither advocate derailed by persistent questioning.

Waxman’s chief nemesis was Justice Antonin Scalia, who repeatedly challenged him to name a single case in U.S. or British legal history in which a foreign alien imprisoned outside a nation’s sovereign territory had been given habeas rights.

Waxman said the court had already decided in Rasul v. Bush that Guantanamo was effectively under U.S. control. He insisted that, in fact, the federal government had more power over the detainees in Guant�namo, which is under U.S. military control under an agreement with Cuba, than it would if they were in prison in Kentucky, where state sovereignty could come into play.

Waxman also offered up case after case to answer Scalia’s query, only to have Scalia disagree with each one. “Line them up,” Scalia taunted Waxman at one point. Eventually Waxman surrendered so he could move on to other points, telling the court with a smile, “I have to plead exhaustion.”

Clement’s chief needler was Justice David Souter, who persisted in questioning Clement’s claim that the new review process, which can go as far as the U.S. Court of Appeals for the D.C. Circuit, is constitutionally adequate. When Clement noted that each detainee is entitled to a personal representative during a status review process – not necessarily a lawyer – Souter countered that this representative is required to report back to the military anything that might be unfavorable to the person he is representing.

“He’s not in the position of counsel as we understand the term,” said Souter, who proceeded to challenge Clement on most of his other points.

In the process, Clement sought to reassure the justices that on review, a detainee could challenge many aspects of the detention and even win release. Some of his concessions seemed to go beyond what the government had previously said could be part of the detainees’ review process.

Clement even seemed to impress World War II veteran Justice John Paul Stevens, who wrote prior decisions siding with detainees, that the new procedure was comparable to the treatment of prisoners of war required by the Geneva Conventions.

But the main audience for the Waxman-Scalia and Clement-Souter confrontations was probably Justice Anthony Kennedy, the presumed swing vote in the cases.

Kennedy was unusually quiet during the oral argument and did not seem to relish his role as the decider, as he sometimes does. When Justice Ruth Bader Ginsburg flatteringly quoted Kennedy as ruling that Guantanamo was “in every practical respect” U.S. territory, Kennedy seemed to scowl.

Kennedy tipped his hand only once. It came when Clement, pressed by Justice Stephen Breyer, said the high court could, in deciding the case his way, nonetheless tell lower courts to expedite review in light of the detainees’ already-lengthy detention at Guantanamo.

“How can we fit your position when we have no jurisdiction here?” Kennedy interjected, referring to the law’s exclusion of the federal courts from habeas review.

“If you win, we never get to these issues,” Souter chimed in, and Kennedy added, sarcastically and cryptically, “Have a nice day, everybody.”

Seemingly picking up on Kennedy’s skepticism, Waxman, a partner at Wilmer Cutler Pickering Hale & Dorr, rose for an impassioned rebuttal that put the issues in personal terms.

Waxman told the justices about Murat Kurnaz, a German resident and Guantanamo detainee who was released in 2006 after years of unsuccessful efforts to prove that he had no relationship to terrorists. Coincidentally, The Washington Post ran a lengthy story about Kurnaz this past Wednesday.

Kurnaz was able to win his freedom only because he had a lawyer – which the new appeals process does not guarantee – and because he was able to obtain information about the charges against him and then prove the information was false, according to Waxman.

Those opportunities would not be available to detainees under the appeals process envisioned by Congress, Waxman said. “That is why it is inadequate.”

This article originally appeared in Legal Times, a publication of ALM.