Yesterday the Supreme Court heard arguments in what may be the most important constitutional case of the decade: whether the men detained at Guantanamo have a right to a fair trial before a real court. I spoke with Erwin Chemerinsky about the case – he’s professor of law at Duke, and Dean of the new UC Irvine law school; and he represents one of the Gitmo detainees whose case is before the court, Salem Gherebi.

At issue is the Military Commissions Act, passed by Congress in 2006. Chemerinsky called it "one of the worst laws in all of American history with regard to civil liberties." The provision before the court yesterday says that no non-citizen held as an enemy combatant shall have any access to federal courts, including by writ of habeas corpus. They can go through a military proceeding–if one is convened by the government – and then they can get reviewed by the Court of Appeals for the District of Columbia circuit.

The key issue, Chemerinsky said, "is there’s nothing in the Military Commissions Act that requires that a military proceeding be convened. The government can hold all of these people for the rest of their lives without ever bringing them before a military tribunal. Then the have no ability ever to go before a federal court." And no matter how long they are held, they can’t come to federal court with a writ of habeas corpus.

The Constitution says the right of habeas corpus shall not be suspended, "except in cases of rebellion or invasion." "I don’t think there’s a rebellion or an invasion," Chemerinsky said, "and I don’t think it matters whether a person is a citizen or noncitizen. The government can’t keep a person locked up forever without due process."

John Yoo, former deputy assistant attorney general for George W. Bush, now professor of law at UC Berkeley, defends the Military Commissions Act. On NPR recently he argued that granting terrorists the right to a regular trial in a regular court would hamper the war on terror and give aid and comfort to the enemy.

"He’s assuming they ARE terrorists," Chemerinsky replied. "The whole point is that we don’t know. My client has been in Guantanamo for more than five years, and I still have no idea why he’s there. Maybe he’s a dangerous person, or maybe he’s there because the US paid a warlord who picked him out because they wanted to get the bounty. The only way we can know if somebody is a terrorist or a criminal is to have due process of law."

Yoo argues that we should trust the military when they say that only the most important and threatening of our enemies have been detained at Guantanamo.

Chemerinsky replied, "Here I say let’s trust the Constitution. The Constitution expresses a great distrust of executive power. The Constitution is clear that nobody should be able to be held just on the say-so of the executive, without due process."

Court-watchers agree that the vote will be 5-4, with Justice Anthony M. Kennedy holding the swing vote. If Kennedy votes for the plaintiffs, what happens then? Do they actually get a real trial in a real court with real lawyers?

"Not for years to come," Chemerinsky replied. "Then what will happen is that we’ll go back to federal district court, where they can present their habeas petitions. Then the issue is going to be what does due process and international law require for these detainees. And my guess is that’s going to be fought over for a long time, then appealed to the DC Circuit, then it will go to the Supreme Court.

"The sad reality is that, even if my client wins today at the Supreme Court, what my client wins is the prospect of going to court for years to come. The problem is that if my client loses today, he loses his lawyer and he can be held forever without ever getting his day in court."

John McCain recently commented, "it’s not about who they are, it’s about who we are." Chemerinsky agreed: "That about sums it up," he said.