Short Record as Judge Is Under a Microscope

But in a handful of cases, Roberts has had to weigh in on high-profile issues.

In Hamdan v. Rumsfeld, Osama bin Laden's alleged chauffeur and bodyguard, Salim Ahmed Hamdan, challenged the validity of a military panel's determination that he was an enemy combatant who could be tried before a military commission.

In November 2004, U.S. District Judge James Robertson agreed with Hamdan, saying he was entitled to prisoner-of-war status under the 1949 Geneva Conventions unless a court decided otherwise.

But on July 15, a three-judge panel that included Roberts ruled for the Bush administration.

Roberts joined an opinion, written by Judge A. Raymond Randolph, ruling that the military commissions are legal under a congressional resolution of Sept. 18, 2001, that authorized President Bush to "use all necessary and appropriate force" against al Qaeda and its backers.

Additionally, the opinion said that the Geneva Conventions cannot be enforced by U.S. courts.

Roberts's skepticism about the Endangered Species Act came in his first written opinion on the court, a dissent from the denial of a rehearing sought by a developer in the case of Rancho Viejo v. Norton .

Citing two Rehnquist court cases limiting Congress's power to regulate intrastate activity or noneconomic activity, Roberts suggested that the three-judge panel that had upheld the endangered species law might have acted inconsistently with Supreme Court precedent.

In a recent case involving homegrown medical marijuana in California, however, the Supreme Court has reaffirmed Congress's power to regulate intrastate activity, suggesting that Roberts might have to revisit his 2003 view.

The ex-POWs' case, Acree v. Republic of Iraq , came to the D.C. Circuit as an appeal by the Bush administration.

The district court had entered a judgment in favor of the POWs, awarding them $957 million out of the new Iraqi government's treasury, in part because the U.S. government had missed a deadline to intervene on behalf of Iraq.

Judges Harry T. Edwards and David S. Tatel dismissed the suit on the grounds that federal law did not permit suits against states that sponsored terrorism, but rather only against individual officials or agents.

Roberts went further. He argued that a 2003 law lifting economic sanctions against Iraq gave Bush the power to bar all terrorism-related claims against Iraq and its officials for conduct under regime.

For all their disagreement, however, Roberts and his two colleagues were careful to note that they could understand each other's point of view.

"We acknowledge that this is a close question," wrote Edwards, joined by Tatel.

"I agree with the majority that this question of statutory interpretation is close, and I do not suggest that the [statute] is unambiguous," Roberts replied.