Rumors are once again circulating that the administration is planning/hoping to shut down the military prison at Guantanamo asap. Yesterday's NY Times story adverted to the further legal issues that would arise were that to happen: Detainees moved to locations clearly within the U.S. might thereby become entitled to greater constitutional protection (though no greater statutory protection, because the Military Commissions Act (MCA) of 2006 draws no distinctions based on where an alien is held); meanwhile, human rights issues would be raised by deporting/extraditing detainees to countries where they would face torture, etc.
Here I'll very briefly raise a different question: What would be the long-term meaning of a decision to close Gitmo in the next few weeks or months? We might think that this would show just how weak our courts are in the face of a determined executive. After all, despite repeated losses in the courts, the administration will have succeeded in holding detainees for over half a decade, and ultimately evading any real consequences of Supreme Court decisions rejecting sweeping executive claims. We might call this the "legal realist" take, and it would call attention to the disconnect between the law as announced by the courts and the facts on the ground.
I'm quite sympathetic to the legal realist view, but I also want to suggest that by closing Gitmo, the Bush administration would be losing the long-term legal battle. Here Lincoln is a useful example. Scholarly treatments of Lincoln's assumption of emergency powers call attention to how he got away with bending---we might equally say breaking---the Constitution to fight the Civil War. But for a variety of reasons, the Supreme Court never upheld Lincoln's most aggressive moves on the merits. Indeed, the most notable decisions to come out of the Civil War are odes to the constitutional constraints on the President: Ex Parte Milligan and Ex Parte Merryman are perhaps the leading examples. It's true that the Lincoln won The Prize Cases but the result in that case---that the President can respond to an attack without prior authorization by Congress---seems obviously correct. Likewise, the most disturbing decision from the era is Ex Parte McCardle, which permitted Congress to withdraw habeas jurisdiction over a pending case---but the consensus reading of McCardle makes its result turn on the availability of other avenues of relief. That's a fairly technical way of making a fairly simple point: By any measure, Lincoln exercised sweeping powers during the Civil War, but the legal legacy of the period was much more mixed because the Supreme Court did not validate the most sweeping measures.
Accordingly, even though the MCA effectively overrules Hamdan v. Rumsfeld (and then some!), if we make it through this period without the Supreme Court ever having to uphold the MCA, the legacy of the Bush administration will not be the fact that it effectively exercised sweeping power but that the Supreme Court rejected its boldest assertions of power. This is really the converse of the point made by Justice Jackson in his Korematsu dissent. Jackson complained about the Court validating military judgment and thereby giving it the force of law; invalidation of executive authority---even if it has little practical effect in the immediate circumstances---can act as a brake on executive action in future crises.
And no, I'm not saying that George W. Bush is like Abraham Lincoln or vice-versa, except in this one respect.