Initial Report of the U.S. to the UN Committee Against Torture (October 15, 1999) [emphasis added]:
Torture is prohibited by law throughout the United States. It is categorically denounced as a matter of policy and as a tool of state authority. Every act constituting torture under the Convention constitutes a criminal offense under the law of the United States. No official of the government, federal, state or local, civilian or military, is authorized to commit or to instruct anyone else to commit torture. Nor may any official condone or tolerate torture in any form. No exceptional circumstances may be invoked as a justification of torture. U.S. law contains no provision permitting otherwise prohibited acts of torture or other cruel, inhuman or degrading treatment or punishment to be employed on grounds of exigent circumstances (for example, during a “state of public emergency”) or on orders from a superior officer or public authority, and the protective mechanisms of an independent judiciary are not subject to suspension. The United States is committed to the full and effective implementation of its obligations under the Convention throughout its territory.
Alberto Gonzales's confirmation hearing (Jan 5, 2005):
SEN. LEAHY: … I asked a specific question: Does the president have the authority, in your judgment, to exercise a commander-in-chief override and immunize acts of torture?
MR. GONZALES: With all due respect, Senator, the president has said we’re not going to engage in torture. That is a hypothetical question that would involve an analysis of a great number of factors.
Everyone except the most craven administration apologists understands the only acceptable answer is that not even the President can authorize torture. A lawyer who doesn't understand this is at best a fool or a knave. If he's a government official, however, there are other, far baser, options.