"It is a foundation of this court to test the lawfulness of military tribunals," attorney Neal Katyal told the justices.
With Chief Justice John Roberts sitting out because he previously ruled on the case in a lower court, the justices seemed split on whether the military tribunals established by President Bush following the Sept. 11, 2001, terror attacks were constitutional.
More consensus appeared to be in reach on an 11th-hour question thrown at the court in the form of a congressional statute stripping U.S. courts of judicial oversight in the prosecution of Guantanamo Bay detainees. The government's argument that the statute should apply retroactively to cases pending when it became law last December was not greeted enthusiastically.
A trio of justices seemed particularly irked at the statute itself, which the government argued stripped detainees of habeas corpus relief, which refers to the right of a prisoner to be brought before a judge to determine whether or not he or she is being imprisoned lawfully.
"Whether or not the writ of habeas corpus was suspended, you are leaving us with the position of the United States that the Congress may validly suspend it inadvertently? Is that really your position?" asked an incredulous Justice David Souter.
"At least when you're talking about the extension of the writ to enemy combatants..." Solicitor General Paul D. Clement began to reply.
"Now wait a minute. The writ is the writ. There are not two writs of habeas corpus," Souter interrupted.
Justices John Paul Stevens and Stephen Breyer also accused the Bush administration of running with an interpretation that the vaguely worded statute didn't necessarily support. While the court has not been asked to address the constitutionality of the Detainee Treatment Act (DTA), several justices indicated they might do so because its effect is to suspend habeas corpus.
Habeas corpus may only be suspended during invasion or insurrection, according to the Constitution. Justice Anthony Kennedy noted two years ago in another detainee case that the Habeas Corpus Act makes no distinction between citizens and foreigners when it grants prisoners access to a judge to review their detention.
The court had previously denied the administration's request to dismiss those cases summarily, including Tuesday's Hamdan v. Rumsfeld, opting to take on for itself how the statute should be applied.
Katyal, who was representing Salim Ahmed Hamdan, said the statute was "not a model of clarity," and pointed out it did not explicitly state it applied to all pending appeals.
Hamdan, a Yemeni national, has been in U.S. military custody at Guantanamo Bay Navel Base since June 2002. Though he admits to being Usama bin Laden's personal driver and bodyguard, he denies any role in the Sept. 11 attacks.
Hamdan has been charged with conspiracy to commit terrorism and is one of 10 detainees out of 490 to have been formally charged by the United States. His attorney challenged the legitimacy of the special military commission that will try him, arguing that it does not sufficiently adhere to the Uniform Code of Military Justice or 1949 Geneva Convention and that President Bush did not have the authorization to form the commission in the first place.
Katyal also urged the court to reject the government's conspiracy charge against Hamdan. Conspiracy is generally not considered a legitimate war crimes charge because it is overbroad and easy to abuse.
"This is not an ordinary criminal trial applying lawful ordinary procedures. This is an ad hoc trial in which the procedures are all defined [by] the president. He says the laws of war do not apply when we're talking about protecting this vulnerable individual at Guantanamo, but then he says they do apply and permit him to charge Mr. Hamdan with the one offense which is rejected entirely in international law," Katyal said.
Katyal also argued that Hamdan was entitled to Geneva protections, under which he would have had an independent assessment of his combatant status rather than one by the Combatant Status Review Tribunal, which found that he was an enemy combatant but won't release any evidence for that finding on national security grounds.
One of the government's long-running claims in the War on Terror has been that the executive has authority vested in him by the Constitution to take extraordinary measures to protect the nation in wartime. Simultaneously, it has departed from traditional rules of war, including those pertaining to prisoners of war, because it says Al Qaeda is not a traditional enemy.
Because the president determined Hamdan to be a member of Al Qaeda and enemy combatant, the government argued that he was not entitled to prisoner of war status — and trial by court-martial — or Geneva protections.
"If he is any different from any prisoner of war, it is because he has disentitled himself to some protections," Clement said.
An exasperated Breyer repeatedly prodded Clement to clear up what the justice saw as contradictions in the government's claims.
"I take [your] argument as saying you want to try a war crime. You want to say this is a war crimes tribunal. One, this is not a war — at least not an ordinary war. Two, it's not a war crime because [conspiracy] does not fall under international law. And three, it's not a war crimes tribunal or a commission because there is no emergency, it's not on the battlefield, the civil courts are open, there is no military commander asking for it," Breyer said.
"If the president can do this, well, then he can set up a commission to go to Toledo and in Toledo pick up an alien and not have any trial at all except for that special commission," the justice continued.
"I think the events of 9/11 speak to the fact that this is a war where the laws of war are involved," Clement replied, adding that conspiracy was considered a war crime during the Civil War.
"Judicial review after a final decision is the general rule," Alito said, pointing to the fact that Hamdan was questioning a military commission that had yet to try him. "You're assuming bad faith on the part of those making these decisions."
Clement pointed out that the military commission's word wasn't necessarily final.
"He can make the argument he wants to make in the commission. If the commission rejects the argument, then there will be review of that decision in the court of appeals in the concrete record," Clement said. Under the DTA, the U.S. Court of Appeals for the District of Columbia Circuit has exclusive jurisdiction to review the commission's procedures.
Several justices later asked Katyal what would happen if the government charged his client with a more typical war crimes charge or uncovered more serious evidence against him.
"The government has had four years to get their charges together on Mr. Hamdan. This is the government's charge against him," Katyal replied.
The case is Hamdan v. Rumsfeld, 05-184.