The essay analyzes the issue of same sex couples' right to marry from a State level perspective. Before describing different models of recognizing same sex couples’ rights, the essay deals with the argumentative structure of State Courts decisions in an attempt to demonstrate that the continued interaction among legal formants fosters the recognition of rights. The State Supreme Courts indeed seem to develop a conter-majoritrian attitude that encourages a theory of constitutional interpretation that conceives constitutions as evolving documents. The volume collects the works of scholars in the fields of Constitutional Law and International Law and represents the first attempt to analyze case-law of national, supranational and international jurisdictions (and quasi-juridictions) as regards the legal status of same-sex couples. It is foreworded by prof. Gráinne de Búrca.