DIFFERENCES between the early and late American presidency are easy enough to recognize. The twentieth-century executive branch is larger than its nineteenth-century counterpart, more apt to introduce and supervise legislative programs like the Great Society, and less shy about invoking veto powers. Similarly, twentieth-century presidents more often rely upon “unilateral” powers such as the withholding of documents from Congress under the auspices of “executive privilege” or the initiation of executive agreements instead of Senate-approved treaties. These developments, which are the preoccupation of a great many presidential scholars, are undeniable.  But what we often forget is a much simpler, much more important, fact: The single greatest difference between early and contemporary American presidencies is the expansion of the role of rhetoric.