States cannot keep same-sex couples from marrying and must recognize their unions, the Supreme Court says in a ruling that for months has been the focus of speculation. The decision was 5-4.Justice Anthony Kennedy, seen as a pivotal swing vote in the case, wrote the majority opinion. All four justices who voted against the ruling wrote their own dissenting opinions: Chief Justice John Roberts and Justices Antonin Scalia, Clarence Thomas and Samuel Alito.Comparing the ruling to other landmark decisions, NPR's Nina Totenberg says, "This is probably right up there with Brown v. Board of Education, and Roe v. Wade — if you like it or hate it — and today, Obergefell v. Hodges. This was a historic moment."The opinion includes more than 100 pages; we've embedded it near the bottom of this post.Update at 11:30 a.m. ET: 'Our Love Is Equal,' Obergefell SaysToday's ruling "affirms what millions across this country already know to be true in their hearts: our love is equal," says lead plaintiff Jim Obergefell, who challenged Ohio's ban on same-sex marriage.Obergefell continued, "the four words etched onto the front of the Supreme Court — 'equal justice under law' — apply to us, too."He filed suit because he wasn't allowed to put his name on his late husband John Arthur's death certificate after Arthur died from ALS. Holding a photograph of Arthur as he spoke today, Obergefell said, "No American should have to suffer that indignity."Obergefell has been traveling from Cincinnati to Washington every week, to be sure he would be in the court when a decision was announced in his case.Update at 11:15 a.m. ET: 'Like A Thunderbolt,' Obama SaysSpeaking at the White House, President Obama praises the Supreme Court's ruling, saying it arrived "like a thunderbolt" after a series of back-and-forth battles over same-sex marriage.Obama says the ruling "will strengthen all of our communities" by offering dignity and equal status to all same-sex couples and their families.The president calls the ruling "a victory for America."Update at 10:37 a.m. ET: More On The Ruling, And Obama's Reaction"The ancient origins of marriage confirm its centrality, but it has not stood in isolation from developments in law and society," Kennedy wrote. His opinion sketches a history of how ideas of marriage have evolved along with the changing roles and legal status of women.Comparing that evolution to society's views of gays and lesbians, Kennedy noted that for years, "a truthful declaration by same-sex couples of what was in their hearts had to remain unspoken.""The nature of injustice is that we may not always see it in our own times," Kennedy wrote after recounting the legal struggles faced by same-sex partners.The Supreme Court said that the right to marry is fundamental — and Kennedy wrote that under the 14th Amendment's protections, "couples of the same-sex may not be deprived of that right and that liberty."In his dissent, Roberts wrote that the court had taken an "extraordinary step" in deciding not to allow states to decide the issue for themselves, saying that the Constitution does not define marriage.Calling the ruling "deeply disheartening," Roberts said that those on the winning side of the issue should celebrate a victory — "But do not celebrate the Constitution," he wrote. "It had nothing to do with it."Justice Scalia said the Supreme Court's "highly unrepresentative panel of nine" had violated "a principle even more fundamental than no taxation without representation."We've covered those dissents in a separate post.Welcoming the news on Twitter, President Obama wrote, "Today is a big step in our march toward equality. Gay and lesbian couples now have the right to marry, just like anyone else. #LoveWins."Our original post continues:The justices ruled in Obergefell v. Hodges, which is linked to three other same-sex marriage cases that rose up through the court system. Together, they involve a dozen couples who challenged same-sex marriage bans in Ohio, Michigan, Kentucky and Tennessee — the only states with bans on marriage between gay and lesbian couples that had been sustained by a federal appeals court.Today's ruling overturned that decision by the 6th Circuit Court of Appeals. As the Supreme Court's summary states, "The history of marriage is one of both continuity and change."The justices had been asked to decide whether the 14th Amendment requires states to a) license same-sex marriages and b) recognize such unions that were made in other states.The 14th Amendment, we'll remind you, was ratified shortly after the Civil War. It has to do with U.S. citizenship — and with providing equal protection for all citizens.Before Friday's ruling, gay marriage had already been made legal in 37 states — by either legislative or voter action or by federal courts that overturned state' bans.As NPR's Nina Totenberg reported when the Supreme Court heard the current case back in April, conservative justices had pointed questions for the attorneys: