Steve Vladeck @ PrawfsBlawg and Orin Kerr @ Volokh on Padilla. Judge Luttig, writing for the Fourth Circuit:

[A]s the government surely must understand, although the various facts it has asserted are not necessarily inconsistent or without basis, its actions have left not only the impression that Padilla may have been held for these years, even if justifiably, by mistake –- an impression we would have thought the government could ill afford to leave extant. They have left the impression that the government may even have come to the belief that the principle in reliance upon which it has detained Padilla for this time, that the President possesses the authority to detain enemy combatants who enter into this country for the purpose of attacking America and its citizens from within, can, in the end, yield to expediency with little or no cost to its conduct of the war against terror –- an impression we would have thought the government likewise could ill afford to leave extant. And these impressions have been left, we fear, at what may ultimately prove to be substantial cost to the government’s credibility before the courts, to whom it will one day need to argue again in support of a principle of assertedly like importance and necessity to the one that it seems to abandon today. While there could be an objective that could command such a price as all of this, it is difficult to imagine what that objective would be.