So we have two different meanings attached to the Promise of American life, and it makes all the difference in the world which we choose. Do we opt for Croly's sense of the Promise as a vast opportunity to transform the human condition and bring into being the New Jerusalem on the American strand? Or do we accept the Founders' more skeptical vision of human nature?

In pondering these questions, one might consider the way that Americans are instinctively drawn, during moments of domestic crisis and uncertainty, to political leaders known for their genuine reverence for the Constitution. Such leaders command our respectful attention, irrespective of party affiliation, precisely because they associate themselves so strongly with the spirit of the Constitution. Of course, it is equally true that Americans, like everyone else, have at times been drawn in the opposite direction, to the charismatic leader, the Theodore...