The threat of terrorism once again raises some of the classic questions about constitutionalism: is it possible for constitutions to do what they aim to do—channel and control political power in such a way as to make it safe and beneficent for those under its rule but also competent to govern? Does not terrorism reraise the Schmittian problem of “the exception”, i.e., the situation of emergency that necessarily escapes all constitutional limitations? Although they did not face the problem of terrorism as we know it, the American founders developed three different models of constitutionalism, embodying three different ways of responding to emergent circumstances and yet remaining bound to the constitutionalist aspiration. We develop the main outlines of the three models both conceptually and historically and show how they continue to be relevant to current discussions of constitutionalism in the age of terror. Finally, we make a tentative effort to judge which of the three models is most able to do what constitutions should do in difficult times.