This Article will examine the validity of a presidential claim of executive privilege when exercised against a congressional inquiry by analyzing positions previously taken by proponents of executive privilege. First, the historical usage theory, often cited as a justification for the privilege, will be reevaluated, and it will be suggested that historical precedeht does not support the existence of such a theory. Second, the separation of powers justification will be undercut by close examination of the constitutional principles involved. Finally, attack will be waged on the various public policy arguments used to support the privilege.