WASHINGTON (Reuters) - U.S. Supreme Court justices signalled a reluctance on Tuesday to rule broadly on the fundamental right to marriage for gays and lesbians, suggesting a potentially anti-climactic outcome in the first of two related cases before the high court.
As sign-waving demonstrators massed outside, the court completed an hour and 20 minutes of oral argument on whether to let stand a California ban on same-sex marriage, without indicating a clear path forward by the end of the session.
It was the first of two days of argument. On Wednesday, the court will consider the 1996 federal Defence of Marriage Act (DOMA), which denies federal benefits to married same-sex couples. Rulings in both cases are expected by the end of June.
The narrower DOMA case does not give the court the same opportunity to issue a broad ruling because the case relates only to a federal law that limits the definition of marriage to opposite-sex couples for the purposes of federal benefits.
Only the California Proposition 8 case gave the court the option of finding a constitutional right for same-sex couples to marry. Polls show growing support among Americans for gay marriage.
But during the argument, Justice Anthony Kennedy, who is considered a swing vote, raised concerns about the court entering "uncharted waters" on an issue that divides the states.
Kennedy even raised the prospect of the court dismissing the case, a relatively unusual move that would leave intact a federal appeals court ruling that had earlier struck down the California law, known as Proposition 8.
In a similar vein, Justice Samuel Alito also urged caution, noting that gay marriage, as a concept, is "newer than cellphones and the Internet."
None of the justices indicated support for the Obama administration's favoured solution, which would strike down Proposition 8 and require the eight states that already recognize civil unions or domestic partnerships to allow gays and lesbians to marry.
Outside the court, hundreds of demonstrators from both sides gathered. Anti-gay marriage protesters marched past the imposing Supreme Court building accompanied by police on motorcycles, drawing jeers and shouts from a pro-gay marriage rally, but there were no physical confrontations.
"No hate - we just disagree!" yelled one marcher, holding a sign that proclaimed children do best with a mother and father.
Jay Golon, a New York City educator who was at the pro-gay marriage rally, said he has many students with same-sex parents. "It's a family," he said. "That's all."
Several hundred people rallied against same-sex marriage on the National Mall, carrying such signs as "Kids Do Best With a Mom and Dad" and "Same-sex Marriage is Not Marriage."
Inside the hushed courtroom, filled to capacity with lawyers and spectators, some of whom had waited for days to get a seat, the justices probed lawyers on both sides on the technical issue of whether California opponents of gay marriage even had a right to be heard in federal court.
Although there was no apparent consensus on that point, if the court were to find the proponents did not have standing it would not reach the merits and then the federal district court ruling that struck down Proposition 8 would be left intact.
U.S. citizens in general do not have a right to sue to enforce laws they favour. Chief Justice John Roberts pressed lawyer Charles Cooper, who represents gay marriage opponents, on why his clients are any different as they seek to enforce Proposition 8.
"I don't think we've ever allowed anything like that," Roberts said.
On the broader question of same-sex marriage, pressed by attorney Theodore Olson on behalf of two California same-sex couples, some conservative justices raised concerns about a lack of scientific data on same-sex couples raising children.
Justice Antonin Scalia said there is "considerable disagreement" about whether gays and lesbians should be able to raise children.
Kennedy agreed that there is "substance to the point that sociological information is new."
On the liberal wing, justices probed Cooper on his assertion that the government's interest in promoting procreation is a primary reason for limiting the definition of marriage.
Cooper said that expanding marriage "could well lead, over time, to harms" to the institution of marriage.
Both Justice Elena Kagan and Justice Stephen Breyer questioned Cooper on how his definition of marriage squares with the fact that infertile opposite-sex couples can marry.
"There are lots of people who get married who can't have children," Breyer said.
Prior to expressing his doubts about whether the court should decide the case, Kennedy pressed Cooper on the "imminent legal injury" facing almost 40,000 California children being raised by gay and lesbian couples. "They want their parents to have full recognition and full status," he said.
(To follow oral arguments both days, visit the Reuters live blog at reut.rs/scotus1)
Reporting by Lawrence Hurley and David Ingram; Additional reporting by Joseph Ax, Ian Simpson and Joan Biskupic; Editing by Kevin Drawbaugh, Howard Goller and Eric Beech