In Federalist No. 51, one of eighty-five essays written to urge New York to ratify the Constitution, James Madison clearly describes the fundamental challenge in creating a system of government:

If men were angels, no government would be necessary. If angels were to govern men, neither external nor internal controls on government would be necessary. In framing a government which is to be administered by men over men, the great difficulty is this: you must first establish government to control the governed; and in the next place oblige it to control itself.

The men at the Constitutional Convention had begun to believe that a government that is too weak, such as the one created by the Articles of Confederation, would lead to anarchy. Out of this anarchy some charismatic individual might come forward and become a dictator. On the other hand, the framers...