This Article analyzes the central provision of the recently en-acted Fiscal Compact, which directs member states of the European Union (EU) to incorporate into their constitutions a “golden rule”—that is, a requirement that yearly budgets be balanced. The purpose of the Article is to examine—by surveying the introduction of these pervasive budgetary constraints in four selected EU member states (Germany, France, Italy and Spain)—the institutional implications that the “golden rule” has on the role of the political and judicial branches, both in the states and in the EU as a whole. The Article argues that, while the domestic effects of the “golden rule” are likely to vary from one state to another, the Fiscal Compact systematically enhances the powers of the EU institutions to direct and police the budgetary policies of EU member states, thus increasing centralization in the EU architecture of economic governance. The Article then contrasts this development with the federal experience of the United States. A comparative perspective sheds light on the fact that, while most U.S. states are also endowed with constitutional “golden rules,” the federal government never played a role in their adoption and is barred from interfering with the budgetary processes of the states. In conclusion, the Article suggests that an unexpected paradox emerges in the new constitutional architecture of the EU: Although in crafting the institutional response to the Euro-zone crisis state governments have repeatedly discarded a U.S.-like federal model as being too centralized and centripetal for the EU, they have ended up establishing a regime that is much less respectful of state sovereignty than the U.S. federal system.