For the ancient philosophers, constitutionalism meant classifying regimes and constructing regimes to form virtuous citizens. In the modern world it generally means checks and balances, institutional mechanisms limiting the power of government and protecting private rights. In Democracy in America Tocqueville attempts to combine both views in his interpretation of the U.S. constitutional system. He employs the regime analysis of ancient constitutionalism to understand the new phenomenon of popular sovereignty and its potential for despotic control over the minds and characters of citizens. At the same time, he shows how the constitutional devices found in the United States—such as federalism, judicial review, and the separation of powers—can be adapted to inculcate a kind of moral virtue by teaching citizens to exercise liberty with moral responsibility and to govern themselves. The result is a constitutional theory that weaves ancient and modern principles into an original and coherent whole.