The moment Justice Anthony Kennedy said the words — “Section 3 of DOMA is in violation of the Fifth Amendment” — a muffled cheer pierced the quiet in the Supreme Court chamber.

Heads turned to the audience and security officers looked for the offender, but the celebration was just beginning.

A few minutes later, as the dissenting Justice Antonin Scalia was accusing the majority of making opponents of same-sex marriage look like “enemies of the human race” and “unhinged members of a wild-eyed lynch mob,” those seated near the chamber’s windows heard vibrations that sounded at first like a helicopter.

But this was no aircraft: Word that the court had just dismantled the Defense of Marriage Act and thereby removed federal obstacles to same-sex marriage had made its way from the courtroom to news broadcasts and finally to the hundreds of gay-rights supporters massing in front of the court. Their cheers echoed over the marble facade, across the cloistered courtyards and into the hallowed chamber itself.

Twenty minutes later, after the justices announced a second opinion that killed off a California ban on gay marriage, the same-sex couples who had brought the case against the California law emerged from the courthouse with one of their lawyers, David Boies, and raised their linked hands in triumph at the top of the steps.

The crowd chanted, “Thank you! Thank you!” and then, “USA! USA!”

“Today is a great day for American children and families,” lead plaintiff Kristin Perry said into the microphones as her partner, Sandra Stier, stood at her side. “Sandy and I want to say how happy we are not only to be able to return to California and finally get married, but to be able to say to the children in California … ‘No matter what family you’re in, you are equal.'”

Gay-rights advocates could not reasonably have hoped for a better result than the one the Supreme Court gave them on its final day in session: Kennedy joining with the court’s liberal justices to condemn the federal law discriminating against same-sex marriage, and Chief Justice John Roberts leading an ideologically mixed majority in refusing to reinstate California’s Proposition 8 because the law’s defenders lacked legal standing. The combined effect was to make clear that the court would not stand in the way of the inexorable march toward marriage equality.

Kennedy spoke conversationally but delivered a moral denunciation of DOMA for stigmatizing same-sex couples and humiliating their children. “No legitimate purpose overcomes the purpose and effect to disparage and to injure those whom the state, by its marriage laws, sought to protect in personhood and dignity,” he argued.

Roberts, who surprised many with his ruling in favor of “Obamacare” last year, did so again on this session’s final day. He didn’t address the legality of same-sex marriage but, by refusing to prop up Prop 8, his opinion had the same result. Roberts merely said that those citizens trying to defend the California ban had only “a generalized grievance,” which “no matter how sincere is insufficient to confer standing.”

Scalia agreed with Roberts on that, giving the chief justice conservative cover. But Scalia’s criticism of Kennedy’s ruling in the DOMA case went on for nearly 12 minutes — longer than Kennedy took to announce it. While Kennedy sat, chin on fist, Scalia ridiculed the majority’s “self-aggrandizement” and “clumsy” intervention, and he accused his colleagues of “real cheek” for their “lengthy lecture on how superior the majority’s moral judgment in favor of same-sex marriage is.”

Seconds after Roberts adjourned for the summer, a woman’s exultant cry echoed through the court’s central foyer and was quickly met with shushing. But there was no quieting the hundreds who had gathered on the sidewalk, many waving rainbow flags or signs thanking the plaintiffs. A gay men’s chorus assembled. More people joined the celebration.

Some wept for joy, some cheered or took photos, and all perspired in the brutal heat. The few opponents of same-sex marriage were mostly on the edges of the carnival. Police tried to hold back the crowd as the plaintiffs reached the cameras.

“Today the court said that I am more equal, that we are more equal,” plaintiff Jeff Zarrillo told the tangle of journalists and celebrants. “I look forward to growing old with the man I love.”

That man, Paul Katami, stepped to the microphones. “Today,” he said, “I finally get to look at the man that I love and finally say, ‘Will you please marry me?'”

The two men then sealed it with a kiss.

Dana Milbank is an American political reporter and columnist for The Washington Post. Email to danamilbank@washpost.com.