Fédéralisme et mariage entre personnes du même sexe. Quelques enseignements après Windsor

The case United States v. Windsor, judged by the Supreme Court of the United States in June 2013, posed a double issue: first, the existence or not of constitutional basis for the federal definition of marriage (DOMA), a matter connected with federalism and the balance of power in the U.S. federal system, and second, the case question concerning the validity and federal recognition of same-sex marriages celebrated according to States’ law. To the extent that the contemporary debate on the normative princi-ples of federalism is in a phase of profound doubts and interrogations, it may be useful to analyze the key findings of Windsor on federalism, for the sake of a better understanding of the federal principle in advanced democ-racies. On the other hand, to the extent that federalism is, as we shall see, the key to Windsor judgment, we will try to explain how federalism can be considered an effective argument in the defense and promotion of same-sex marriage. Windsor’s analysis should help, on the one hand, to a better understanding of what federalism means in democracy, and on the other, to clarify the terms of democratic debate on same-sex marriage, often more or less disconnected from some fundamental democratic principles (majority rule, separation of powers, etc.).