Half of the states in the country have moved to ban gay nuptials since the Massachusetts high court's landmark decision in late 2003. But New Jersey has been among a few states that instead have chosen to extend new rights to same-sex couples.
Gay-rights advocates are seeking to build upon a limited domestic-partnership law that the Legislature enacted two years ago by securing full marriage benefits from a liberal-leaning court that once cited the Boy Scouts for discrimination.
''New Jersey is a unique state nationally when it comes to this issue,'' said David Buckel, marriage project director for the gay-rights group Lambda Legal, who will argue the case Wednesday. ''That became very clear with a governor's race in which candidates on both sides opposed an amendment to the state constitution that would limit marriage to a man and a woman.''
Seven gay and lesbian couples in long-term relationships, some of whom have raised children together for more than 30 years, sued the state in 2002, long before gay marriage exploded onto the national political stage. They argued that a state statute defining marriage as a union of heterosexual couples ''marginalizes an entire class of citizens'' - and violates broad equal-rights protections in the state's constitution.
Despite rejections at the trial and appellate court levels, lawyers and scholars say the New Jersey Supreme Court could cut ahead of similar suits pending in Washington, California, New York, Maryland, Connecticut and Iowa by swiftly legalizing gay marriage.
''New Jersey's court has a long and proud history of interpreting cases in favor of civil rights, and a victory in this case would be in keeping with that tradition,'' said Sally Goldfarb, a family law professor at Rutgers University Law School in Camden who studies family law issues. ''The New Jersey Supreme Court has not hesitated to overturn state laws, and so these litigants are in a better position than they would be before most other courts across the country.''
New Jersey conservatives are girding themselves for what they foresee could be another ''activist'' ruling from a court that in 2000 struck down parental notification for abortions and in the 1970s decided one of the first right-to-die cases in favor of the family of brain-damaged Karen Ann Quinlan.
''We're hopeful the court will save us aggravation and leave things the way they are,'' said Len Deo, president of the New Jersey Family Policy Council. ''But if they overturn laws here, we'll seek whatever remedy is in our realm, including a state constitutional amendment.''
Deo and other advocates who have joined in the state's case say New Jersey's high court will be hard-pressed to abandon strong trial and appellate court rulings.
''The way we see it, the appellate decision really got it right by recognizing that legally the reason the state is in the marriage business is for the protection of children,'' said Chris Stovall of the Marriage Litigation Center at Arizona's conservative Alliance Defense Fund.
Assistant Attorney General Patrick DeAlmeida's primary argument is that defining marriage is a task for the Legislature, not the courts - and that New Jersey lawmakers instead chose to extend an inheritance-tax exemption and hospital-visitation and decision-making rights through the domestic-partnership law.
That argument could backfire, said Nathaniel Persily, a professor at the University of Pennsylvania Law School.
''New Jersey is trying incrementally to bring gay couples into the same regime of benefits as heterosexual couples,'' Persily said. ''But then the question for the court becomes, if you're willing to go that far, why don't you go all the way?''
The New Jersey State Bar Association has filed a friend-of-the-court brief in the case, contending that the domestic-partnership law has created a confusing legal mess. Its position reflects comments from same-sex couples who have said they felt betrayed when hospitals refused to recognize their union or when public employers declined to offer health benefits to partners.
''We're trying to lay out for the court the reasons this law just doesn't work,'' said Peggy Knee, a vice president of the bar association. ''It presents difficulties for couples, difficulties for attorneys who try to plan for them, and the bottom line is the equality is just not there.''
''People who believe in traditional marriage feared the Massachusetts decision would open the floodgates to usher in a great wave of same-sex marriage legalization,'' said Stovall, of the Alliance Defense Fund. ''That hasn't happened. The decision just hasn't had any coattails.''
But same-sex marriage advocates have plotted a careful course of state-level lawsuits that they predict will ultimately yield victories in key states. The big question, they say, is whether New Jersey, California or Washington will be the next to legalize gay nuptials.
A pair of Washington cases that had been victorious at the trial-court level were argued before the state's Supreme Court nearly a year ago, and a ruling is expected any day.
''Any time a disenfranchised group has fought for liberty and equality, we have seen a patchwork across the country as some states move forward and others lag behind. This was true with racial equality, women's equality and, in perhaps the closest parallel, interracial marriage,'' said Buckel, of Lambda Legal. ''Each time discrimination ends in any state, it becomes obvious that the sky didn't fall.''