The US Supreme Court [official website] on Friday ruled [opinion, PDF] 5-4 in Obergefell v. Hodges [SCOTUSblog materials] that states must issue marriage licenses to same-sex couples and also must recognize same-sex marriages that take place in other states. The ruling strikes down same-sex marriage bans in 15 US states. Those defending the laws had argued both that justifications for opposite-sex marriage were different than those for same-sex marriage and that the issue should be decided by the states. Writing for the court, Justice Anthony Kennedy said the right to marriage for same-sex couples was required by the equal protection clause [LII backgrounder] of the Fourteenth Amendment:

Four principles and traditions demonstrate that the reasons marriage is fundamental under the Constitution apply with equal force to same-sex couples. The first premise of this Court’s relevant precedents is that the right to personal choice regarding marriage is inherent in the concept of individual autonomy….

A second principle in this Court’s jurisprudence is that the right to marry is fundamental because it supports a two-person union unlike any other in its importance to the committed individuals….

A third basis for protecting the right to marry is that it safeguards children and families and thus draws meaning from related rights of childrearing, procreation, and education… .

Finally, this Court’s cases and the Nation’s traditions make clear that marriage is a keystone of the Nation’s social order….

The limitation of marriage to opposite-sex couples may long have seemed natural and just, but its inconsistency with the central meaning of the fundamental right to marry is now manifest.

The decision reverses an earlier ruling [opinion, PDF] by the US Court of Appeals for the Sixth Circuit [official website] .

Chief Justice John Roberts as well as Justices Antonin Scalia, Clarence Thomas and Samuel Alito each wrote a dissent. The dissenting justices argued that the equal treatment of opposite-sex and same-sex marriages could not be read into the Constitution and that by making its ruling, the majority had interfered with a state-by-state democratic process, which they pointed out had already been tending toward granting same-sex couples greater rights. The court granted certiorari to the case in January and heard oral arguments [JURIST reports] in April. Same-sex marriage [JURIST backgrounder] has been an extremely controversial issue in both the US and countries around the world.