This Article breaks new ground by applying the philosophical framework of liberal neutrality (most famously articulated by John Rawls) to the United States Supreme Court’s jurisprudence on marriage. At first blush, the Court’s decision in Obergefell v. Hodges—the culmination of marriage rights—seems to affirm a central principle of liberalism, namely equal access to marriage regardless of sexual orientation. Gays and lesbians can finally take part in an institution that celebrates the union of two committed individuals. But perversely, in its attempt to expand access to marriage, the Court has simultaneously entrenched values that are antithetical to the basic tenants of liberal neutrality. Working at the nexus of political theory and constitutional law, this Article provides the first critique of marriage as an illiberal union. It focuses on three problems with the current state of marriage: one, marriage is problematically a spiritual—not secular—status, affirming an intangible quality that threatens the separation of church and state; two, in marrying couples, the state stigmatizes those who choose not to marry; and three, by promoting monogamy, marriage unreasonably excludes alternative adult relationships and even permits the state to criminalize certain kinds of sexual activity. By questioning the legitimacy of the institution itself, this Article breaks from the usual focus on the issue of access. It ultimately suggests a radical rethinking of the relationship between marriage and the state’s role in regulating it, where marriage becomes a private contract rather than a state-sanctioned, civil institution.