Michigan, Kentucky, Ohio, and Tennessee, are among the states that define marriage as a union between one man and one woman. Ps are same-sex couples, and Ds are state officials responsible for enforcing the laws in question. Ps sued in their home states and each district court rules in their favor. The Sixth Circuit reversed the judgments. The Court of Appeals held that a State has no constitutional obligation to license same-sex marriages or to recognize same-sex marriages performed out of State. The Supreme Court granted certiorari.