On Tuesday, the state Supreme Court declined to review a case brought by three same-sex couples who claiming the Minnesota Defense of Marriage Act discriminates against them and against the son of one of the pairs.

The plaintiffs, who were all legally married elsewhere, filed suit [PDF] in 2010 in state court after Hennepin County refused to issue them marriage licenses. After a trial court judge dismissed the suit, the couples, who constitute the nonprofit Marry Me Minnesota, appealed. In January, the Court of Appeals overturned the dismissal ruling.

The Supreme Court’s decision not to review the case means the matter may now proceed to trial in Hennepin County. There’s very little chance it will be resolved before next fall’s amendment vote.

News that the case will move forward is not likely to spark universal celebration among advocates of same-sex marriage, some of whom fear it could be used to fuel arguments in favor of amending the state constitution to ban gay marriage.

The plaintiffs and their attorneys have disagreed, saying they simply want to be married and plan to win on the merit of the case.

Robbinsdale residents Douglas Benson and Duane Gajewski were married in 2000 in Vermont and in Ontario in 2003. Because Minnesota refuses to recognize their marriage, they may not share retirement benefits, nor are they guaranteed legal recognition as a couple should one of them become ill.

Thomas Trisko and John Rittman registered with the city of Minneapolis as domestic partners in 1991, were religiously married in their church, St. Mark’s Episcopal Cathedral, in 1999, and legally in Winnipeg in 2005. In their 60s, they are increasingly concerned about their lack of legal standing in matters involving health care and survivorship.

Jessica Dykhuis and Lindzi Campbell were married in Iowa last year and have a son, Sean Campbell. Their registry as domestic partners with the city of Duluth affords them no legal rights, and they are unable to provide each other health insurance.

Hennepin County Judge Mary DuFresne dismissed the lawsuit a year ago, relying in her reasoning on a 1971 Minnesota Supreme Court decision, Baker vs. Nelson. In January, the state Court of Appeals overturned DuFresne’s ruling, noting among other things that since Baker the U.S. Supreme Court has indicated that “moral disapproval of a class because of sexual orientation cannot be a legitimate government purpose that equal protection requires.”

The issue that was appealed to the high court [PDF] was whether the appeals court was right to dismiss the case against the state, which was originally a co-defendant along with Hennepin County Registrar Jill Alverson, the local official overseeing marriage licenses. If the court had agreed to hear Alverson’s petition to review that ruling it would have simply delayed the case’s return to the trial court.