WASHINGTON – Like many a nervous suitor thinking about popping the question, several Supreme Court justices Tuesday pondered making gay marriage the law of the land and said, each in his or her own way, “I’m just not ready.”

Hearing its first-ever gay-marriage case, on whether the Constitution allows California voters to ban such unions, the high court seemed to be seeking an escape hatch.

And while there was no majority consensus about what that escape hatch might be, at least three of the justices indicated that perhaps they had made a mistake in taking the case – a mistake they could correct by dropping the matter and letting stand an appeals-court ruling legalizing gay marriage in California but not in other states that have banned it.

“I just wonder if the case was properly granted,” said Justice Anthony M. Kennedy, who is often the swing vote on the nine-member court.

“Why did we grant cert?” asked Justice Antonin Scalia, using Supreme Court slang for granting certiorari, the legal term for taking a case. “We should let it percolate.”

Even one of the liberal justices, Sonia M. Sotomayor, appeared to agree. “If the issue is letting the states experiment and letting the society have more time to figure out its direction, why is taking a case now the answer?” Sotomayor asked.

Those comments came amid an impassioned 80-minute argument that centered on two key legal questions: Whether the Constitution’s guarantee of equal protection under the law gives gays the right to marry, and whether the gay-marriage opponents who brought the case even have standing to sue.

In response to the first question, Theodore B. Olson – the Republican lawyer who successfully argued another case before the Supreme Court that resulted in George W. Bush winning the presidency in 2000 – contended there is no doubt that California’s marriage ban treats gays as unequal citizens.

“It walls off gays and lesbians from marriage – the most important relation in life, according to this court, thus stigmatizing a class of Californians based upon their status and labeling their most cherished relationships as second-rate, different, unequal and not OK,” said Olson, who joined his Bush v. Gore opponent, Democrat David Boies, in arguing for gay marriage.

Attorney Charles J. Cooper argued on behalf of the supporters of Proposition 8, the 2008 California referendum that overturned state court decisions and banned gay marriage in the state. “The concern is that redefining marriage as a genderless institution will sever its abiding connection to its historic traditional procreative purposes and refocus the purpose of marriage and the definition of marriage away from the raising of children and to the emotional needs and desires of adults, of adult couples,” he said.

In response, several justices indicated the court should proceed with caution.

Justice Samuel A. Alito said gay marriage didn’t exist anywhere until the Netherlands approved it in 2000. “You want us to step in and render a decision based on an assessment of the effects of this institution, which is newer than cellphones or the Internet?” he asked.

Kennedy – the author of landmark decisions overturning state sodomy laws and a Colorado referendum that prevented localities from passing gay-rights legislation – noted that gay marriage is so new that it’s difficult to know what its impact on society will be: “We have five years of information to weigh against 2,000 years of history or more.”

Meanwhile, Chief Justice John G. Roberts Jr. said it’s wrong to view marriage as an institution that is deliberately exclusionary.

“When the institution of marriage developed historically, people didn’t get around and say let’s have this institution but let’s keep out homosexuals,” he said. “The institution developed to serve purposes that, by their nature, didn’t include homosexual couples.”

Those purposes included, first and foremost, supporting procreation, Cooper argued, opening up a discussion about gay parents and their children.

Scalia noted “considerable disagreement” among sociologists about the consequences children face when both their parents are of the same sex.

But Kennedy noted that California has long allowed gay adoption and that many of those adopted children strongly favor gay marriage. “There are some 40,000 children in California ... that live with same-sex parents, and they want their parents to have full recognition and full status,” he said. “The voice of those children is important in this case, don’t you think?”

Kennedy was not the only justice who appeared to be arguing both sides of the case.

Most notably, Sotomayor pondered if a federal right to gay marriage would open the door to a similar ruling legalizing polygamy, but she also asked Cooper if there was any rational basis for discriminating against homosexuals in any cases other than marriage.

When Cooper said no, Sotomayor asked: “If they’re a class that makes any other discrimination improper, irrational, then why aren’t we treating them as a class for this one thing?”

It’s quite possible that the court may not even have to answer such questions when it issues its opinion, likely in June.

While the justices could rule that there is a constitutional right to gay marriage, they also could drop the case or affirm the appellate court ruling, which is tailored narrowly to California.

Other options are upholding the California gay marriage-ban or ruling that the gay-marriage opponents who appealed the case, only after the state refused to do so, don’t have legal standing to sue.

The court dwelled at length on that last option.

“Have we ever granted standing to proponents of ballot initiatives?” asked Justice Ruth Bader Ginsburg.

“No, your honor, the court has not done that,” Cooper conceded.

To have standing to sue, the gay-marriage opponents have to prove that they have been harmed by the federal court decisions overturning California’s gay-marriage ban. Sotomayor, for one, couldn’t see the harm: “How does it create an injury to them separate from that of every other taxpayer to have laws enforced?”

The case. called Hollingsworth v. Perry, is the first of two gay-marriage cases before the court.

Today, the court will hear arguments in U.S. v. Windsor on whether the federal government’s 1996 Defense of Marriage Act, which defines marriage as being between a man and a woman and denies federal benefits to couples in state-sanctioned gay marriages, is unconstitutional. That case has special resonance in New York and the eight other states that, along with the District of Columbia, allow gay marriage.

But both cases have great resonance in the gay community, which sees marriage rights as the key to full equality.

The excitement that gays feel about the cases was palpable outside the Supreme Court, where hundreds voiced their support for gay-marriage rights.

The crowd included the Rev. Gene Robinson, the first openly gay bishop in the Episcopal Church. “Who would have ever thought we would live to see this?” Robinson, 65, said.

But nearby, a smaller contingent of gay-marriage opponents made their point clear.

Among them was Mike Krzywonos, 57, of Pawtucket, R.I., who wore a button that read “marriage 1 man + 1 woman.” He told the Associated Press that his group represents the “silent majority.”

Polls, however, show a rapid swing toward support for gay marriage – a fact that may or may not influence the justices.

After the argument, Cooper, the lawyer for the gay-marriage opponents, voiced confidence: “We thought the hearing went very well.”

But Olson, one of the nation’s top Supreme Court litigators, echoed the thoughts of many veteran court-watchers.

“Based upon the questions, I have no idea” what the justices will do, he said.