5 Key Moments in the Supreme Court's Marriage Arguments

The justices, in their own words.

The Supreme Court covered a lot of ground Tuesday in its oral arguments over same-sex marriage, from partisan point-scoring to legalistic confusion about whether marriage is a contract or a law.

Oral arguments are rarely a perfect guide to how the Court will ultimately rule. (Remember how everyone was certain it would overturn Obamacare in 2012?) But they provide two critical opportunities: a chance for the public to understand how each justice is approaching the issue, and a chance for the justices to throw out questions they hope might bring a colleague around to their position.

With those two purposes in mind, here are five key quotes that will help explain what, exactly, went down during Tuesday's historic arguments:

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Anthony Kennedy: "Same­-sex couples say, 'Of course we understand the nobility and the sacredness of the marriage. We know we can't procreate, but we want the other attributes of it in order to show that we, too, have a dignity that can be fulfilled.'"

Kennedy holds the deciding vote in this case, and the biggest takeaway Tuesday was that he hasn't changed his fundamental approach to gay rights. His questions weren't quite as full-throated as some observers had expected, but he returned to some of the same themes that have animated his past decisions on gay rights and same-sex marriage.

Dignity was a central theme in Kennedy's 2013 decision striking down a key part of the federal Defense of Marriage Act. He wrote that DOMA "tells those couples and all the world, that their otherwise valid marriages are unworthy of federal recognition," relegating them to "a second-tier marriage" that "demeans the couple, whose moral and sexual choices the Constitution protects."

It was that kind of language, in the 2013 ruling, that led Justice Antonin Scalia to predict Kennedy would ultimately take the same view toward state bans on same-sex marriage.

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And the dignity of the institution was still on Kennedy's mind Tuesday, even as John Bursch, the attorney defending states' bans on same-sex marriage, argued that marriage only exists to promote childbirth and family stability—not as a recognition of the emotional bond between two spouses.

"I thought that was the whole purpose of marriage. It bestows dignity on both man and woman in a traditional marriage. "¦ I think many states would be surprised, with reference to traditional marriages, they are not enhancing the dignity of both the parties. I'm puzzled by that," Kennedy said.

Ruth Bader Ginsburg: "You're not taking away anything from heterosexual couples. They would have the very same incentive to marry, all the benefits that come with marriage."

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Bursch struggled against aggressive questioning from the Court's liberal wing to explain why states have a good reason to exclude same-sex couples from marriage. Even if promoting a good family structure for children really is a state's main interest in promoting marriage, the justices asked, how would same-sex marriages undermine that interest?

"It has to do with the societal understanding of what marriage means. "¦ When you change the definition of marriage to delink the idea that we're binding children with their biological mom and dad, that has consequences," Bursch replied.

This line of questioning lasted several minutes and helped lead the debate toward Kennedy's questions about dignity and the other purposes of marriage. It's not the institution of marriage itself that makes people good or bad parents, Ginsburg and Justice Sonia Sotomayor argued—so that's not a compelling reason to ban same-sex unions.

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"How many married couples do fathers, with the benefits or the requirements of marriage, walk away from their children?" Sotomayor asked. "So it's not that the institution alone does it and that, without it, that father is going to stay in the marriage. He made a choice."

Kennedy: "Under your view, it would be very difficult for same-­sex couples to adopt some of these children. ... You had some premise that only opposite-­sex couples can have a bonding with the child. That was very interesting, but it's just a wrong premise."

Bursch's long focus on marriage and procreation didn't do him any favors. Not only did Kennedy argue that marriage serves other, additional functions (like dignity), he also suggested that same-sex marriage could help promote the very family stability Bursch was invoking.

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This, too, was a callback to Kennedy's reasoning in the 2013 DOMA ruling. The federal law "humiliates tens of thousands of children now being raised by same-sex couples" and "makes it even more difficult for the children to understand the integrity and closeness of their own family and its concord with other families in their community and in their daily lives," he wrote then.

John Roberts: "People feel very differently about something if they have a chance to vote on it than if it's imposed on them­­ by the courts."

This argument—which figures prominently in the states' written briefs, even though it took a backseat during Bursch's argument time Tuesday—is probably the conservative argument most likely to appeal to Kennedy.

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Kennedy is sensitive to the balance of state and federal power. And, as Roberts noted, public opinion on same-sex marriage has shifted rapidly—so why not let that trend continue, without forcing it on states that might not be ready?

Similarly, Scalia said state laws legalizing same-sex marriage would leave more room than a constitutional standard when it comes to religious exceptions, such as ministers who don't want to perform same-sex ceremonies.

Mary Bonauto, who argued against the marriage bans Tuesday, said states have had no trouble reconciling marriage equality with religious exemptions.

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"Because it was a state law. That's my whole my point," Scalia replied. "If it's a state law, you can make those exceptions. But if it's a constitutional requirement, I don't see how you can."

Roberts: "You're not seeking to join the institution. You're seeking to change what the institution is."

In addition to urging a go-slow approach to let the voters work their will, the Court's conservatives questioned whether same-sex marriage is a new institution—maybe too new for the Court to confidently end the public debate over it and not one that's already protected by the Constitution or the Court's precedents.

The point wasn't lost on Kennedy, who said the definition of opposite-sex marriage "has been with us for millennia."

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"How do you account for the fact that, as far as I'm aware, until the end of the 20th century, there never was a nation or a culture that recognized marriage between two people of the same sex?" Justice Samuel Alito asked Bonauto.

The conservative justices pressed Bonauto on the history of homosexuality and same-sex marriage, both to prove the newness of same-sex marriage and to establish that gay people and opposite-sex marriages lived side by side for centuries.

"Ancient Greece is an example," Alito said. "They had marriage, didn't they? ... And they had, ­­and they had same­-sex relations, did they not? "¦ People like Plato wrote "¦ approvingly of same-­sex relationships, did he not? "¦ So their limiting marriage to couples of the opposite sex was not based on prejudice against gay people, was it?"

"I can't speak to what was happening with the ancient philosophers," Bonauto replied.