With the United States Supreme Court poised to issue rulings whose impact may be felt for years to come, the marathon legal battle over same-sex marriage faces its moment of truth.
Unless the justices fail to agree on two same-sex marriage cases before the court, and decide to revisit the matter when they reconvene later this year, the final opinions will be issued on Wednesday.
With the court shrouded in secrecy, a frenzy is expected when the panel presided over by conservative Justice John Roberts divulges whether the definition of marriage can be extended to include same-sex couples.
In a country where 12 US states plus the capital allow gays and lesbians to marry, the top court is due to take a stance on two appeals and decide whether the principle of equality defended by the constitution has been violated.
In the first case, a gay widow from New York, Edith Windsor, backed by the Obama administration, is challenging the federal Defense of Marriage Act (DOMA).
That controversial 1996 law denies gay and lesbian couples the same federal rights and benefits that heterosexual married couples take for granted, from tax breaks and welfare benefits to access to a hospitalized spouse.
The second case deals with the constitutionality of California's Proposition 8, a 2008 ballot initiative that saw the nation's most populous state ban same-sex marriage.
At its hearing at the end of March, the top court seemed ready to repeal DOMA but reluctant to legalize gay marriage in California.
The court could rule on California alone, on the states that have similar legislation on civil unions, or on those that still ban gay marriage.
Analysts say the decisions could go either way.
"This term, in particular, it's very risky to bet on what the Supreme Court will do," said lawyer Elizabeth Wydra of the Constitutional Accountability Center.
As with most of the important cases, Justice Anthony Kennedy, who usually votes with the right, "could be the deciding factor," she said.
David Cruz, law professor at the University of Southern California, said it was very unlikely that the court would adopt a broad ruling that strikes down all gay marriage bans.
"I think seeing all same-sex couples being able to get married in every state is probably not going to happen immediately ... because of the tradition in the court: the Justices often move in steps, they rule incrementally," he said.
Thomas Keck, political science professor at Syracuse University, said that whatever the justices decide, "it is going to be high-profile and it is going to get lots of attention."
Fifty-three percent of Americans support gay marriage, according to a recent survey by the Gallup polling institute.
A Pew Research Center survey found that 47 percent of nearly 500 gay marriage news stories studied between March 18 and May 12 -- a period marked by Supreme Court deliberations -- primarily focused on support for the measure.