David Cole exposes in a marvellous short piece why Yoo was so influential with Bush's administration and, yet, why his position is absolutely flawed.
Yoo was extremely influential because he said exactly what Bush wanted to hear: that the President has virtually absolute freedom as far as foreign affairs are concerned. Yoo then gave legitimacy to that claim by wrapping it in a very influential philosophy of constitutional interpretation, that is originalism.
But the problem is, as Cole suggests, that an originalist interpretation of the American Constitution only show that the Framers wanted the executive to be closely checked by Congress. This applies to both treaty making and war declarations. This point sounds very convincing considering also that the Founding Fathers were deeply influenced by Republican writings, which strongly insisted on the political accountability of the executive.
Thus, if Yoo achieves anything, this is the complete bending of the intentions of the framers. Cole goes on wondering whether that bending is normatively justified after 9/11. In other words, he charitably asks whether Yoo's flawed originalist position is still justified on political grounds arising from the present international context.
Cole' s answer to that question is possibly more stifling than his opinion on Yoo's originalism, and righly so. Cole argues that the flexibility granted by Yoo's interpretation has had atrocious consequences. America, who once played by International rules, and was perceived as the 'good cop' in the global arena, is now regarded as the 'bad cop' because of its willingness to crash its enemy with whatever means.
Moreover, it is very difficult to redress the present situation. Trying prisoners held in guantanamo now, would mean to espose the US to the review of the interrogation technique uses with them. Thus, it is probably preferable to reach a private compromise with those prisoners in order to avoid public blame. But the problem is that the international community is already blaming the US for what it did. We are therefore left with a deadlock, which will not be easily unlocked.