The case of Salim Ahmed Hamdan, Osama bin Laden's former driver in Afghanistan, has the potential to become one of the most important US Supreme Court decisions of this generation.
It will test the scope of presidential power in the war on terror. It may clarify how detained Al Qaeda suspects are treated by the US. More broadly, it challenges the justices to further define the balance of power among the three branches of government during times of national emergency.
But before the high court takes up those weighty issues of constitutional law, it must decide a more basic question: whether it has jurisdiction to hear the case. If the justices decide the case is not yet ripe for their review, Mr. Hamdan's appeal ends there, at least for the time being.
That is the unusual posture surrounding the Hamdan case on the eve of oral arguments Tuesday - litigation so multilayered that the high court has taken the unusual step of allotting 90 minutes for oral arguments, a half hour more than usual.
The Bush administration, in its court brief, says Hamdan's appeal is "fatally premature." The Detainee Treatment Act, signed into law Dec. 30, 2005, bars federal judges and justices from hearing any appeals by Guantánamo detainees before a verdict is rendered by a military commission in their war-crimes cases, argues US Solicitor General Paul Clement.
The Hamdan case will signal how the Supreme Court views its role in the war on terror, say critics of the military-commission process. "Given the triumphalist orientation of this administration and the passivity of Congress, anything that gives us a better feel for how energetic the courts will be as a counterweight is critical," says Eugene Fidell, president of the National Institute of Military Justice.
Hamdan is being held in open-ended detention at the US terror prison camp at Guantánamo Bay, Cuba. In 2004, he was set to stand trial for allegedly conspiring with top Al Qaeda leaders to commit acts of terrorism, charges he denies. Shortly before his trial was to start, a federal judge in Washington ruled that the military- commission process violates both US law and the Geneva Conventions.
That decision was reversed by a federal appeals court panel. In November, the Supreme Court agreed to take up the case, examining whether military commissions at Guantánamo had been properly authorized by Congress or were otherwise authorized by the inherent powers of the president as commander in chief of the armed forces.
In addition, the court agreed to examine whether a federal judge can force the US government to apply the 1949 Geneva Conventions - international accords that define prisoners of war and how they are to be treated - to Guantánamo detainees.
The Bush administration maintains that detained Al Qaeda suspects don't qualify for the Geneva protections. Hamdan's lawyers say their client and others at Guantánamo are covered.
Under normal circumstances, those two questions would set the stage for constitutional fireworks. But the Hamdan case features extra twists.
Less than two months after the high court agreed to hear Hamdan's appeal, Congress approved the Detainee Treatment Act, which bars detainees from filing pretrial challenges in federal court. The law is aimed at heading off a flood of federal lawsuits by Guantánamo detainees.
The big question is whether that law applies to Hamdan. The US says Hamdan's pretrial appeal must be dismissed, and that he can file an appeal later if he is convicted by a military commission.
Hamdan's lawyers say the Detainee Treatment Act doesn't apply to their client. They say Congress was aware of the Hamdan case when it passed the law - and that it amended the bill to avoid undermining the pending Supreme Court case. "The 'plain' language of the enacted law is most fairly read as not applying to this case, or at the very least is ambiguous," wrote Hamdan lawyer Neal Katyal in a brief.
Mr. Katyal says under the government's reading the Detainee Treatment Act may preclude Hamdan from ever raising a constitutional challenge to the military- commission process.
"Hamdan's claims turn on federal statutes, treaties, and constitutional provisions about presidential authority - questions within this court's, not a commission's, expertise," Katyal says. If the government's view is embraced by the high court, he adds, Hamdan may be deprived of his day in court both now and forever.
Those who support the Bush administration's position argue that Hamdan will have his day in court. Under the Detainee Treatment Act, he can appeal the decision of his military commission to a special court made up of three federal judges from the District of Columbia Circuit Court of Appeals. "The DTA is quite clear that this special appeal to this specially composed court of the D.C. Circuit is the only judicial review," says Andrew McBride, a Washington lawyer who filed an amicus brief on behalf of former attorneys general and retired military officers supporting Defense Secretary Donald Rumsfeld.
At its core, Hamdan's case is a test of the military-commission process. Hamdan's lawyers say such commissions are unlawful because they fail to provide the same level of fair procedures and protections as US and international law.
Solicitor General Clement counters that President Bush has ample authority to subject captured enemy combatants to trial by military commission both through congressional authorizations and his inherent commander-in-chief powers. Passage of the Detainee Treatment Act, he adds, is Congress's endorsement of Mr. Bush's decision to convene military commissions at Guantánamo.
The Hamdan case will be the first big terrorism-related case to come before the Supreme Court since the death of Chief Justice William Rehnquist and the retirement of Justice Sandra Day O'Connor. "They were really in the forefront of establishing the Supreme Court as a defender of its own power," says Deborah Pearlstein, a lawyer at Human Rights First who has worked on briefs supporting Hamdan's case. "So it's a pretty significant test," she says, even though the new chief justice, John Roberts, has recused himself because he ruled on it as a judge on the D.C. Circuit Court of Appeals.
• Staff writer Linda Feldmann contributed to this report.