Several Supreme Court justices on Wednesday indicated interest in striking down a law that denies federal benefits to legally married same-sex couples, presenting the possibility of a major change in a few months in gay marriage law.
Justice Anthony Kennedy, a potential swing vote, warned of the "risks" that the Defense of Marriage Act (DOMA) infringes upon the traditional role of the states in defining marriage.
The 1996 U.S. law denies married same-sex couples access to federal benefits by defining marriage as between a man and a woman. Kennedy referred to DOMA as "inconsistent" because it purports to give authority to the states to define marriage while limiting recognition of those determinations.
The court is expected to issue a ruling by the end of June.
On the liberal side of the bench, Justice Sonia Sotomayor and Justice Elena Kagan echoed some of Kennedy's concerns about the states' rights issue.
"What gives the federal government the right to be concerned at all about the definition of marriage?" Sotomayor said.
Justice Ruth Bader Ginsburg also raised concerns about the law, stressing how important federal recognition is to any person who is legally married.
"It affects every area of life," she said.
Comparing marriage status with types of milk, Ginsburg said that a gay marriage endorsed by a state, but not recognized by the federal government, could be viewed as the equivalent of "skim milk."
The law is the focus of a second day of oral arguments before the high court as it tackles the gay marriage issue.
It is possible the court would not reach the wider issue in the DOMA case because of preliminary legal matters relating to whether the court can hear it.
On that issue, conservative justices criticized the decision by President Barack Obama to abandon the legal defense of DOMA and called into question his willingness to defend other laws passed by Congress and challenged in court. "It's very troubling," Kennedy said.
While the criticisms may not affect how the justices eventually rule, it showed frustration with how Obama has walked a difficult political line on gay marriage.
Obama and his attorney general, Eric Holder, said in February 2011 they would cease defending the law because they believed it to be invalid under the Constitution.
In the place of the Justice Department, Republican lawmakers have stepped in to argue for the law.