• G.W. Bush argued that "unitary executive" power exempted him from most congressional oversight

President Bush's use of signing statements was part of larger theory of the presidential office labeled the unitary executive. Simply defined, this theory argues that the president's constitutionally allocated executive responsibilities may not be restricted by Congressional or Judicial action. Thus, his authority to hire and fire executive employees or exercise his responsibilities as commander-in-chief cannot be abridged. Congressional creations like the Environmental Protection Agency—an "independent executive agency"—represents, this theory suggests, something of a contradiction in terms: an inappropriate effort on the part of Congress to create an executive agency that is not fully controlled by the executive branch.

It is not a particularly new theory; the question is really only whether the framers intended for ours to be a "strongly unitary" or "weakly unitary" executive. In other words, whether the president was to be absolutely shielded from all congressional encroachments on his duties, or whether Congress has the legitimate right, within its legislative functions, to impose some case-specific limitations on executive prerogatives.

The debate is not likely to go away. In fact, given the growing complexity of governance in the twenty-first century, it may be just beginning. As the United States faces the challenge of combating international terrorism—an enemy that requires more complex forms of resistance than the traditional enemy nation-state—and as the character of regulatory legislation (for example, over the all-but-indecipherable tangle of contemporary banking practices) grows more complex, one suspects that the tendency might be for a further extension of presidential power or a further drift toward the unitary executive.

Just over a hundred years ago, Theodore Roosevelt set the example of the modern president as he addressed the more complex economic and social needs of the modern era. One hundred years from now, will George Bush—today a leader deeply unpopular and frequently ridiculed as among our most inept presidents—be identified as the key figure in the evolution of the modern presidency?