In the case Baker v. Nelson the Supreme Court dismissed the case on the grounds of "want of a substantial federal question". Two university student activists sought to get a same-sex marriage.
Since the nation's Founding, the institution of marriage has been an institution that was within the jurisdiction of individuals and churches, and if nothing else the states. After the case of Obergefell v. Hodges, Nelson was overturned and the institution of marriage was nationalized.