BOSTON — The Massachusetts Supreme Judicial Court is poised to issue a ruling — possibly as early as this weekend — in a case that many gay activists predict will legalize gay marriage in Massachusetts.

If the court requires the state to open up marriage to same-sex couples, the decision may dramatically alter the legal landscape for gay and lesbian couples in Massachusetts, and possibly the country, according to some legal experts.

A ruling on the case could come as early as this Friday, July 11. Under court rules, decisions are to be rendered within 130 days of oral argument in a case. That deadline would fall this weekend in the marriage case, making a decision likely either this Friday, July 11, or Monday, July 14. But exceptions have been made in the past for controversial rulings, so a ruling is not guaranteed on that timeline.

But Jennifer Levi, a senior staff attorney for Gay & Lesbian Advocates & Defenders and co-counsel in the case, cautioned that the state’s high court might not rule in favor of the plaintiffs and could throw the matter back to the legislature.

“That’s what they did in Vermont,” Levi said. “Or we could lose and the court could say for some reasons that the guarantees of equality under the state’s constitution do not apply to gay and lesbian couples.”

The Vermont Supreme Court ruled in December 1999 that excluding same-sex couples violated their rights under the state’s constitution. But rather than striking down the law, the court gave the state legislature one year to find some remedy for the inequity. The legislature and then-Gov. Howard Dean, now a candidate for the Democratic presidential nomination, responded by adopting “civil union” legislation that created “separate but equal” legal recognition for gay couples.

Opponents of gay marriage in Massachusetts say that if the court legalizes same-sex marriage, thousands of gay and lesbian couples from other states will flock to Massachusetts to get married. Then, they will return to their home state, where their marriages may not be acknowledged, creating a tidal wave of lawsuits.

“One of our arguments all along has been that [the gay marriage debate] is a legislative matter not a judicial one,” said Ron Crews, executive director of the Massachusetts Family Institute. a group opposed to gay marriage.

Crews, a former Georgia legislator, said that 37 states and the federal government have Defense of Marriage Acts on their books defining marriage as the union of a man and woman. Nebraska and three other states have taken their respective DOMAs a step further and imposed a “super” DOMA that not only bans recognition of same-sex marriage, but any kind of recognition of same sex relationships, including domestic partnerships and civil unions.

Traditionally, states have denied same-sex couples rights because of their DOMA laws, Crews said. But he added that things would be different if a gay couple from Georgia got married in Massachusetts and brought back to their home state a marriage license instead of a domestic partnership certificate.

“Even before you get to the initial question, ‘How do other states treat marriages that a couple entered into lawfully?’ that’s a common law question that the courts address consistently,” Levi said. “But once you get to the constitutional question, ‘Can it trump DOMA?’ Well, that’s another question.”

Levi said gay couples were likely to challenge anti-gay marriage laws that she said single out gay couples for discrimination. She also said that many of the legal cases would seek to determine if state and federal DOMA laws are in violation of the U.S. Constitution’s Full Faith & Credit Clause, which holds that states must “recognize the public acts, records, and judicial proceedings of other states.”

“It does seem to me that the Full Faith & Credit Clause is brought to bear on the recognition of marriage,” agreed Sue Hyde a field director for the National Gay & Lesbian Task Force in Massachusetts, a public and political advocacy group.

“This is why our opponents are desperate, at both the state and federal level, by implementing statutory and constitutional prohibitions. They are stumbling over themselves to get these prohibitions in place because the Full Faith & Credit Clause would require recognition of same-sex couples across state lines,” she said.

Legal scholars who have researched the topic have noted that some courts have found an exception to the Full Faith & Credit Clause when accepting another state’s laws is found to be against “the public policy” of the state. Older cases have applied this “public policy” exception, for example, to allow states the option of not recognizing polygamous marriages from Utah.

Mass. amendment postponed

Crews said that the state’s joint-judiciary committee heard a measure that would amend the state’s constitution to define marriage as the union of a man and woman. It has now been presented to the state’s Constitutional Convention, which has postponed any action on the bill until Nov. 12. The bill has 13 co-sponsors.

The state’s constitution could not be amended until 2006 because the process takes two legislative sessions, Crews said.

But should the highest court in Massachusetts legalize gay marriage and order the state to issue marriage licenses from now until 2006 when the constitution may be amended, Crews said, he was uncertain of the fate of marriage certificates “already existing” at the time the amendment is passed.

A similar amendment effectively banning gay marriage was proposed in Massachusetts last summer, but State Sen. Tom Birmingham (D) refused to let the Constitutional Convention hear or vote on the proposal. Proponents of the measure, who collected 100,000 signatures from citizens, cried foul and said they were denied “a referendum process.”

Levi said that it was unlikely that the state’s constitution would be amended. “The most recent public opinion poll demonstrates that the majority of Massachusetts citizens support equality for marriage for gay and lesbian couples,” Levi said. “If people were asked to vote on this question [of a state amendment], many would see the specific harm that a constitutional amendment would have on their neighbors and their children’s classmates’

parents. I believe voters would resoundingly reject that kind of a wholesale exclusion that would have a devastating effect on those relationships that will hopefully be recognized.”

Crews also acknowledged the great deal of time and effort it would take to amend the state’s constitution and allowed that 2006 would be “political unknown territory.”

“Regardless of the ruling, we are pressing ahead and our state legislator [Rep. Philip Travis (D-Rehoboth, Mass.)], who is sponsoring the amendment, has agreed to press ahead for a vote in the constitutional convention,” Crews said.

Plaintiffs vow fight regardless of ruling

Ed Balmelli and Mike Horgan, who will mark their nine-year anniversary this December, knew that their commitment ceremony in Massachusetts a few years ago would not amount to much legally.

That fact was made apparent to them when a friend of theirs died at home and the partner of the deceased couldn’t sign the coroner’s release to have the body removed because the survivor was not a “next of kin.”

“That was scary and prompted my partner and me to get wills drawn up, powers of attorney and that sort of thing,” Balmelli said. “It gets expensive when you consider that for just $25 you can get a marriage license in the state of Massachusetts.”

Balmelli and his partner soon joined six other couples in Massachusetts and filed a lawsuit arguing that the freedom to marry the person of one’s choice is protected under the state’s constitution. Many independent organizations, from the Boston Bar Association to the Urban League of Eastern Massachusetts have also joined the plaintiffs.

GLAD filed the suit, Goodridge vs. Department of Public Health, in April 2001.

Balmelli said he and his fellow plaintiffs will keep fighting for marriage rights, regardless of the court’s ruling.

“I have many [straight] friends who say, ‘You know, I think you and your partner are wonderful people and are deserving of all the rights we have as a married couple but I think you need to call [gay marriage] something else,’” Balmelli said.

“And I always say, ‘Well, if we are going to be hung up on a word, then we should start breaking down all aspects of marriage.’ If someone is divorced and gets remarried, it should be called ‘remarriage’ not ‘marriage’ and then we should have ‘special marriage’ and ‘secondary marriage.’ When I put the argument that way, many of my friends say, ‘OK, I see what you mean.’”