Capturing and detaining enemy belligerents like Hamdi is part of the president's war-making powers under Article II of the Constitution. As U.S. courts have recognized, going back to the Civil War, a court can no more review the commander in chief's battlefield detentions than it can, say, overturn his decision to bomb Tikrit. Both would be equally absurd and would equally trespass on the president's fundamental powers.
In a January decision upholding Hamdi's detention, the 4th U.S. Circuit Court of Appeals ruled that the judicial review of battlefield detentions would risk "saddling military decision-making with the panoply of encumbrances associated with civil litigation." The executive makes both the decisions whom to capture and whom to bomb based on determinations that cannot be second-guessed in civilian courts, lest the commander in chief have to argue his every act of war in court.
As the 4th Circuit put it, the Hamdi detention "bears the closest imaginable connection to the president's constitutional responsibilities," and trespassing on those responsibilities "would be an infringement of the right to self-determination and self-governance at a time when the care of the common defense is most critical." In other words, holding enemy belligerents until the end of hostilities, and interrogating them while they are detained, is indispensable to the war on terrorism that the American people have chosen to wage.
A court has no legitimate power to undo that choice, no matter how much Gore and other Bush critics might wish it were so. As for Dershowitz, he will have to look for clients among people not captured on the battlefield with the Taliban.