Which constitutional principles did the Obergefell v. Hodges decision use to protect same-sex marriage?

In the landmark 2015 decision Obergefell v. Hodges, the U.S. Supreme Court ruled that state bans on same-sex marriage are unconstitutional based on two core principles of the Fourteenth Amendment to the U.S. Constitution:1

• Due Process Clause: The Court held that the right to marry is a fundamental right "inherent in the liberty of the person." Because the due process clause prohibits states from depriving any person of "life, liberty, or property without due process of law," the state cannot infringe upon this fundamental liberty.12
• Equal Protection Clause: The Court determined that the right to marry is also guaranteed by the equal protection clause, which forbids states from denying any person the equal protection of the laws. Justice Anthony Kennedy noted the close connection between liberty and equality, asserting that the reasons marriage is considered fundamental apply with equal force to same-sex couples.12

By affirming these principles, the Court established that same-sex couples possess the fundamental right to marry, ensuring that all individuals are treated with the dignity and equality guaranteed by the Constitution.1