In the second day of arguments about gay marriage, the Supreme Court wrestled with the Defense of Marriage Act. The central question is whether the federal government has the authority to define marriage separately from states for the purpose of federal benefits and, if so, whether defining it to the exclusion of gay couples violates the Constitution’s requirement of equal protection under law. Many court watchers opined that most justices seemed inclined to rule in favor of gay rights.

Here are the most revealing moments from the debate:

1. Justice Anthony M. Kennedy questioned whether the federal government is overstepping its authority by defining marriage: “When it has 1,100 laws, which in our society means that the federal government is intertwined with the citizens’ day-to-day life, you are at — at real risk of running in conflict with what has always been thought to be the essence of the state police power, which is to regulate marriage, divorce, custody.”

2. Chief Justice John G. Roberts Jr. has clearly been reading the news of late, a point he referenced in his questioning of attorney Roberta A. Kaplan on the power of the pro-gay-marriage lobby: “You don’t doubt that the lobby supporting the enactment of same-sex marriage laws in different states is politically powerful, do you? … As far as I can tell, political figures are falling over themselves to endorse your side of the case.” Kaplan: “The fact of the matter is, Mr. Chief Justice, is that no other group in recent history has been subjected to popular referenda to take away rights that have already been given or exclude those rights, the way gay people have. … Until 1990 gay people were not allowed to enter this country. … I think gay people are far weaker than the women were at the time of Frontiero.” (Frontiero v. Richardson is a 1973 equal protection case.)

3. Justice Ruth Bader Ginsburg compared marriage to milk in her riff on the extensive federal benefits denied to gay couples under DOMA: “They touch every aspect of life. Your partner is sick. Social Security. I mean, it’s pervasive. It’s not as though, well, there’s this little federal sphere and it’s only a tax question. It’s … as Justice Kennedy said, 1,100 statutes and it affects every area of life. And so he was really diminishing what the state has said is marriage. You’re saying, ‘No, state said two kinds of marriage; the full marriage, and then this sort of skim-milk marriage.’”

4. The heart of Kaplan’s argument for opposing DOMA centered on unlawful discrimination and states’ rights: “No one has identified in this case … any legitimate difference between married gay couples on the one hand and straight married couples on the other that can possibly explain the sweeping, undifferentiated and categorical discrimination of DOMA, Section 3 of DOMA. And no one has identified any legitimate federal interest that is being served by Congress’s decision, for the first time in our nation’s history, to undermine the determinations of the sovereign states with respect to eligibility for marriage. I would respectfully contend that this is because there is none.”

5. Roberts and Kaplan got into a conversation on whether Congress was motivated by animus against gay people when it passed DOMA. Roberts: “So 84 senators … based their vote on moral disapproval of gay people?” Kaplan: “No, I think — I think what is true, Mr. Chief Justice, is that times can blind, and that back in 1996 people did not have the understanding that they have today, that there is no distinction, there is no constitutionally permissible distinction.”

6. Solicitor General Donald B. Verrilli Jr. also addressed the notion that DOMA was passed intentionally to discriminate: “The fundamental reality of it is, and I think the House report makes this glaringly clear, is that DOMA was not enacted for any purpose of uniformity, administration, caution, pausing, any of that. It was enacted to exclude same-sex married, lawfully married couples from federal benefit regimes based on a conclusion that was driven by moral disapproval. It is quite clear in black and white.” Roberts: “So that was the view of the 84 senators who voted in favor of it and the president who signed it? They were motivated by animus?” Verrilli: “Whatever the explanation, whether it’s animus, whether it’s that more subtle, more unthinking, more reflective kind of discrimination, Section 3 is discrimination. And I think it’s time for the court to recognize that this discrimination, excluding lawfully married gay and lesbian couples from federal benefits, cannot be reconciled with our fundamental commitment to equal treatment under law.”

7. Kennedy posited a key question under DOMA: “The question is whether or not the federal government, under our federalism scheme, has the authority to regulate marriage.” Attorney Paul Clement, defending DOMA on behalf of House Republicans: “And it doesn’t have the authority to regulate marriages, as such, but that’s not what DOMA does. DOMA provides certain — DOMA defines a term as it appears in federal statutes.”

8. Clement spoke to Congress’ decision to define marriage in DOMA: “They picked the traditional definition that they knew reflected the underlying judgments of every federal statute on the books at that point. They knew it was the definition that had been tried in every jurisdiction in the United States and hadn’t been tried anywhere until 2004.”

9. Kennedy and Clement had a spirited exchange on the federal government’s decision not to defend DOMA while simultaneously not wanting the case dismissed.

Clement: “Look at Joint Appendix page 437. You will see the most anomalous motion to dismiss in the history of litigation: A motion to dismiss, filed by the United States, asking the district court not to dismiss the case.” Kennedy: “That — that would give you intellectual whiplash. I’m going to have to think about that.”

10. Kennedy was also troubled by the president’s decision not to defend DOMA in the courts. He said: “But let me ask you, suppose that constitutional scholars have grave doubts about the practice of the president signing a bill but saying that he thinks it’s, unconstitutional — what do you call it, signing statements or something like that. It seems to me that if we adopt your position that that would ratify and confirm and encourage that questionable practice, because if the president thinks the law is unconstitutional he shouldn’t sign it, according to some view. And that’s a lot like what you’re arguing here. It’s very troubling.”

11. Verrilli attempted to pull heart strings in giving an example of DOMA’s discrimination: “That means that the spouse of a soldier killed in the line of duty cannot receive the dignity and solace of an official notification of next of kin.”

12. Roberts questioned why the president is still enforcing DOMA, even though he thinks it is unconstitutional: “I don’t see why he doesn’t have the courage of his convictions and execute not only the statute, but do it consistent with his view of the Constitution, rather than saying, ‘Oh, we’ll wait ‘til the Supreme Court tells us we have no choice.’”

13. Clement, defending DOMA, explained why the federal government would want a uniform definition of marriage: “We don’t want somebody, if they are going to be transferred in the military from West Point to Fort Sill in Oklahoma, to resist the transfer because they are going to lose some benefits.”

14. Clement urged the justices to let the democratic process sort out marriage: “That’s what the democratic process requires. You have to persuade somebody you’re right. You don’t label them a bigot. You don’t label them as motivated by animus. You persuade them you are right. That’s going on across the country. … And the federal congress is not immune. They repealed ‘Don’t Ask, Don’t Tell.’ Allow the democratic process to continue.”

John Gramlich contributed to this report.