Federalism, when it has not been ignored altogether in normative political theory, has typically been analyzed in terms that fail to match the institution as it exists in the world. Federations are made up of provinces that are too few, too large, too rigid, too constitutionally entrenched, and too tied to ethnocultural identity to match theories based on competitive federalism, Tiebout sorting, democratic self-government, or subsidiarity. A relatively neglected tradition in liberal thought, based on a separation of loyalties and identifiable in Montesquieu, Publius, Constant, Tocqueville, and Acton, however, holds more promise. If the purpose of federalism is to compensate for worrisome tendencies toward centralization, then it is desirable that the provinces large enough to have political power be stable and entrenched and be able to engender loyalty from their citizens, such as the loyalty felt to ethnoculturally specific provinces. Separation of loyalty theories and the bulwark theories of which they are a subset match up with federalism as it exists in the world.