The case centres on a lawsuit introduced five years ago against the state by three gay couples seeking the right to tie the knot in full equality with heterosexuals. In 1993, the Hawaiian Supreme Court issued a preliminary ruling against the state, saying it had violated the anti-discrimination clauses of its constitution by refusing to issue marriage licences to the plaintiffs.
Given a final chance in the hearings which start in Honolulu today to prove a "compelling reason" why gays should not be allowed to marry, the state is expected to argue that legalising single-sex wedlock could harm the welfare of children that gay couples may wish to raise. Most legal experts doubt that the state will prevail, which could mean final vindication for the plaintiffs some time next year.
That prospect has galvanised conservatives on the mainland, who predict that gays will flood to Hawaii to marry. Because of the "full faith and credit" clauses of the US constitution, which requires all 50 states to recognise the legal decisions of each other, there is the theoretical probability at least that the gays who marry in Hawaii could then claim to be married throughout the union.
The bill before the US Senate, which the House of Representatives approved last month, will formally define marriage as a "union between one man and one woman". Called the "Defence of Marriage Act" (Doma), it will encourage individual states to fight not to recognise gay marriages and ensure that gay couples are denied any federal tax benefits extended to heterosexual couples.
Joe Melillo and Pat Lagon, one of the couples who lodged the suit, expressed dismay at the reaction of mainland politicians. "I think the whole thing has become overblown," Mr Melillo said. "We are not trying to change anyone else's life. People will still be able to procreate and marry as they always have. That is their choice and this our choice. We just want to get married and live happily ever after just like everyone else."
Emotions have none the less been running high in Washington and in state houses across America. At the last count, 15 state legislatures had passed bills, all of dubious constitutional legality, seeking to ignore the full faith and credit provisions in the case of gay marriage. At the same time, however, similar bills have failed in 19 other states.
"What is at stake in this controversy?" Charles Canady, a Republican, asked during the House of Representatives debate. "Nothing less than our collective moral understanding - as expressed in the law - of the essential nature of the family, the fundamental building block of society. This is far from a political issue." President Bill Clinton, a declared gay rights defender, has said he will sign the Doma bill once passed by the Congress.
Dan Foley, the lawyer for the three couples, equates the Hawaii case with the ground-breaking civil rights rulings of Brown versus the Board of Education, which decreed desegregation in schools and Roe versus Wade, which established the right of women to seek abortions. "This will be the biggest civil rights decision ever to come out of this state," he said. Pointing to the relatively humble backgrounds of Mr Melillo and Mr Lagon, who run a T-shirt printing business, he added: "This is not a plot to destroy Western society or bring about some cultural meltdown".
The two men scent victory. "We hope to marry on the day of the final decision," Mr Melillo said. They also hope to raise a child.Reuse content