The Bush Administration has made strong claims about the "inherent" power of the President. These claims are not unprecedented, and they are rarely if ever preposterous; but they are nonetheless bold. Thus it has been argued that the President's inherent authority includes (1) the power to go to war without congressional authorization, (2) the power to engage in foreign surveillance, (3) the power to detain "enemy combatants," including Americans captured on American soil, without access to a lawyer or to hearings, and (4) the power to engage in coercive interrogation of enemies, even torture, when necessary.
One of the jobs of the Department of Justice is to protect the constitutional prerogatives of the President, and after 9/11, it is hardly surprising to find bold claims of this sort. My first goal here is to make some progress in understanding the legal issues by sketching the general framework under which they might be analyzed. My second goal is to suggest that it is often best to refuse to resolve issues of inherent authority, and to answer the legal question while leaving those issues undecided.
It is tempting to take one of two positions on the President's claims of inherent authority. (1) He has such authority under the Commander-in-Chief Clause or the vesting of "executive" power. (2) He lacks such authority, and if he has it, he cannot exercise it without running afoul of the Bill of Rights (eg the Fourth Amendment in the case of surveillance and the Due Process Clause in the case of detention). The debate between (1) and (2) is often very high-level, and forces a judgment about some of the largest unresolved questions in constitutional law.
In his concurring opinion in The Steel Seizure Case, Justice Jackson tried to refine the battle between (1) and (2) by drawing attention to Congress. He suggested that we might also adopt two other positions. (3) The President has such authority because Congress has said that he does, thus augmenting the President's own power with "all that Congress can delegate." (4) The President lacks such authority because Congress has said that he doesn't, ensuring that his own power "is at its lowest ebb."
We have seen (3) in the argument that the President may engage in foreign surveillance because the authorization to use military force implicitly includes the power to engage in such surveillance. We have seen (4) in the argument that FISA bans the President from engaging in such surveillance without going through the FISA process. Naturally, the Department of Justice, attempting to protect the President's prerogatives, emphasizes "inherent" power and implies that Congress lacks the authority to intrude on it.
But there are two other possible arguments, and they are sometimes important. (5) The President has authority because relevant congressional enactments should be construed, if they possibly can, to give him that authority. The reason is that whenever the President has a plausible claim of "inherent" power, statutes should be construed, if they possibly can, to recognize the power that he might well have as a matter of constitutional right. In other words, courts should avoid constitutional questions, and one way to do that is to refuse to adjudicate the President's claim of inherent authority by finding a grant of power from Congress.
(6) The President lacks authority because relevant congressional enactments should be construed, if they possibly can, to deny him that authority. The reason is that there is a plausible claim that the exercise of that authority violates a rights-protecting provision of the Constitution. Courts should avoid constitutional questions by refusing to interpret a statute to allow the president to intrude on constitutionally sensitive interests.
With respect to torture, the Department of Justice's Office of Legal Counsel made argument (5). The particular argument was weak, because the President cannot easily claim that a congressional ban on torture violates his inherent power; but the general form of the argument is fine, in the sense that it is plausible whenever the President has a solid claim of inherent power. The Supreme Court has often made argument (6), even when national security is at risk -- for example, by protecting free speech (Yates) and the right to travel (Kent v. Dulles) in the Cold War, and by protecting due process in World War II (Duncan and Endo).
With respect to wiretapping, argument (5) is available to the government, because there is a plausible claim of inherent power. Argument (6) is available to critics if the Fourth Amendment objection is strong. (It is not clear that it is.) Some of the hardest cases arise when the President has a reasonable claim of inherent power AND when there is a reasonable constitutional objection on the other side.
A final note: One of the less famous parts of Justice Jackson's Steel Seizure concurrence consists of an attack on "loose and irresponsible use of adjectives," including words like inherent, implied, incidental, war, plenary, and emergency. Jackson argued that such words are an effort to "amend" the Constitution. (He deserves special attention on this point, because he was FDR's Attorney General, and hardly oblivious to the constitutional claims of the President.) In so arguing, Jackson probably used the word "amend" too loosely, perhaps even irresponsibly; but he had a point. There is an unmistakable tension between some of the arguments of the Bush Administration, emphasizing inherent authority, and Justice Jackson's opinion in the Steel Seizure Case.
The analysis of the two positions probably has to be conducted issue-by-issue, and not in the abstract. My general point here is that most of the time, it is valuable to avoid disputes between (1) and (2), and to see if progress can be made by bracketing the most fundamental questions about "inherent" authority and by giving careful attention to what Congress has done.