UPDATE 10:27 a.m.: The Supreme Court is indicating it could strike down the law that prevents legally married gay couples from receiving a range of federal benefits that go to married people.
Justice Anthony Kennedy, often the decisive vote in close cases, joined the four more liberal justices Wednesday in raising questions about the provision of the federal Defense of Marriage Act that is being challenged at the Supreme Court.
Kennedy said the law appears to intrude on the power of states that have chosen to recognize same-sex marriages. Other justices said the law creates what Justice Ruth Bader Ginsburg called two classes of marriage, full and "skim-milk marriage."
The federal law affects a range of benefits available to married couples, including tax breaks, survivor benefits and health insurance for spouses of federal employees.
It still is possible the court could dismiss the case for procedural reasons, though that prospect seemed less likely than it did in Tuesday's argument over gay marriage in California.
The motivation behind the 1996 federal law, passed by large majorities in Congress and signed by President Bill Clinton, was questioned repeatedly by Justice Elena Kagan.
She read from a House of Representatives report explaining that the reason for the law was "to express moral disapproval of homosexuality." The quote produced an audible reaction in the courtroom.
Paul Clement, representing the House Republican leadership in defending the law, said the more relevant question is whether Congress had "any rational basis for the statute." He supplied one, the federal government's interest in treating same-sex couples the same no matter where they live.
Clement said the government does not want military families "to resist transfer from West Point to Fort Sill because they're going to lose their benefits." The U.S. Military Academy at West Point is in New York, where same-sex marriage is legal, and Fort Sill is in Oklahoma, where gay marriages are not legal.
UPDATE 9:29 a.m.: In a landmark debate over gay marriage, Justice Anthony Kennedy, a conservative but often a decisive vote, is expressing concern that a federal law that prevents married gay couples from receiving benefits afforded straight married Americans might conflict with state laws.
Kennedy's comment came as other conservative justices on the court seemed skeptical about whether they should even proceed with the case over a challenge to the Defense of Marriage Act.
Kennedy said there was a "real risk" that the challenged statute would conflict with state laws, particularly in income tax cases.
The court is hearing arguments in the case Wednesday on its second day of hearings on gay rights issues. A decision is not expected until the summer.
UPDATE 8:40 a.m.: In the second of back-to-back gay marriage cases, the Supreme Court turned Wednesday to a constitutional challenge to the law that prevents legally married gay Americans from collecting federal benefits generally available to straight married couples, the Associated Press reports.
A section of the 1996 Defense of Marriage Act says marriage may only be a relationship between a man and a woman for purposes of federal law, regardless of state laws that allow same-sex marriage.
Lower federal courts have struck down the measure, and now the justices, in nearly two hours of scheduled argument Wednesday, will consider whether to follow suit.
A somewhat smaller crowd gathered outside the court Wednesday, mainly gay marriage supporters who held American and rainbow flags. One man wore a rainbow flag as a cape. "Two, four, six, eight, we do not discriminate," a group chanted at one point. "If this isn't the time, when is the time? When does equality come into play?" asked Laura Scott, 43, of Columbia, Md.
The DOMA argument follows Tuesday's case over California's ban on same-sex marriage, a case in which the justices indicated they might avoid a major national ruling on whether America's gays and lesbians have a right to marry. Even without a significant ruling, the court appeared headed for a resolution that would mean the resumption of gay and lesbian weddings in California.
Marital status is relevant in more than 1,100 federal laws that include estate taxes, Social Security survivor benefits and health benefits for federal employees. Lawsuits around the country have led four federal district courts and two appeals courts to strike down the law's Section 3, which defines marriage. In 2011, the Obama administration abandoned its defense of the law but continues to enforce it. House Republicans are now defending DOMAin the courts.
Same-sex marriage is legal in nine states and the District of Columbia. The states are Connecticut, Iowa, Maine, Maryland, Massachusetts, New Hampshire, New York, Vermont and Washington. It also was legal in California for less than five months in 2008.
The justices chose for their review the case of Edith Windsor, 83, of New York, who sued to challenge a $363,000 federal estate tax bill after her partner of 44 years died in 2009.
Windsor, who goes by Edie, married Thea Spyer in 2007 in Canada after doctors told them that Spyer would not live much longer. She suffered from multiple sclerosis for many years. Spyer left everything she had to Windsor.
There is no dispute that if Windsor had been married to a man, her estate tax bill would have been zero.
The U.S. 2nd Circuit Court of Appeals in New York agreed with a district judge that the provision of DOMA deprived Windsor of the constitutional guarantee of equal protection of the law.
Like the Proposition 8 case from California, Windsor's lawsuit could falter on a legal technicality without a definitive ruling from the high court.
The House Republicans, the Obama administration and a lawyer appointed by the court especially to argue the issue were to spend the first 50 minutes Wednesday discussing whether the House Republican leadership can defend the law in court because the administration decided not to, and whether the administration forfeited its right to participate in the case because it changed its position and now argues that the provision is unconstitutional.
If the Supreme Court finds that it does not have the authority to hear the case, Windsor probably would still get her refund because she won in the lower courts. But there would be no definitive decision about the law from the nation's highest court, and it would remain on the books.
On Tuesday, the justices weighed a fundamental issue: Does the Constitution require that people be allowed to marry whom they choose, regardless of either partner's gender? The fact that the question was in front of the Supreme Court at all was startling, given that no state recognized same-sex unions before 2003 and 40 states still don't allow them.
But it was clear from the start of the 80-minute argument in a packed courtroom that the justices, including some liberals who seemed open to gay marriage, had doubts about whether they should even be hearing the challenge to California's Proposition 8, the state's voter-approved gay marriage ban.
Justice Anthony Kennedy, the potentially decisive vote on a closely divided court, suggested the justices could dismiss the case with no ruling at all.
Such an outcome would almost certainly allow gay marriages to resume in California but would have no impact elsewhere.
There was no majority apparent for any particular outcome, and many doubts were expressed by justices about the arguments advanced by lawyers for the opponents of gay marriage in California, by the supporters and by the Obama administration, which is in favor of same-sex marriage rights. The administration's entry into the case followed President Barack Obama's declaration of support for gay marriage.
On the one hand, Kennedy acknowledged that same-sex unions had only become legal recently in some states, a point stressed repeatedly by Charles Cooper, the lawyer for the defenders of Proposition 8. Cooper said the court should uphold the ban as a valid expression of the people's will and let the vigorous political debate over gay marriage continue.
But Kennedy pressed him also to address the interests of the estimated 40,000 children in California who have same-sex parents.
"They want their parents to have full recognition and full status," Kennedy said. "The voice of those children is important in this case, don't you think?"
Yet when Theodore Olson, the lawyer for two same-sex couples, urged the court to support such marriage rights everywhere, Kennedy feared such a ruling would push the court into "uncharted waters." Olson said the court similarly ventured into the unknown in 1967 when it struck down bans on interracial marriage in 16 states.
Kennedy challenged the accuracy of that comment: He noted that other countries had had interracial marriages for hundreds of years.
The justice also made clear he did not like the rationale of the federal appeals court that struck down Proposition 8, even though it cited earlier opinions in favor of gay rights that Kennedy had written.
That appeals court ruling applied only to California, where same-sex couples briefly had the right to marry before the state's voters in November 2008 adopted Proposition 8, a constitutional amendment that defined marriage as the union of a man and a woman.
Reflecting the high interest in the cases, the court planned to release an audio recording of Wednesday's argument shortly after it concludes, just as it did Tuesday.
PREVIOUSLY: As we wait for the Supreme Court to convene again at 7 a.m. PDT and begin the second of two historic days hearing oral arguments focusing on legal issues surrounding same-sex marriage, there's a natural question:
Did Day 1 — a case about California's Proposition 8 ban on gay marriage — tell us much about how the justices will tackle Wednesday's case?
NPR's Nina Totenberg told us Tuesday that the short answer is no.
"Except possibly for the fact that there are some people on the court who view same-sex marriage as so new that the democratic process should deal with it, not judges," Nina said, it's unlikely the themes that come up during Wednesday's oral argument will be the same as those the justices zeroed in on Tuesday.
Wednesday's case — a challenge to the federal Defense of Marriage Act — "is a much clearer question of federal benefits applied to people who are married in states where [same-sex] marriage is legal and the democratic process has played out, at least at the state level," Nina said. "The question is whether at the federal level, the federal government can deny those couples the same benefits that the federal government gives to heterosexual couples."
Nina previewed Wednesday's court action on Morning Edition. The court is set to be in session for two hours. As we did Tuesday, we'll be watching for news and updating as the story develops.
For much more about the cases, see:
— SCOTUSBlog's Q on how the "historic Supreme Court gay-marriage case will unfold."