WASHINGTON -- The Supreme Court will take up the issue of gay marriage for the first time, agreeing to rule on a California ballot measure banning the practice, and a federal law defining marriage as solely an opposite-sex union.
The cases, which the court will decide by June, loom as a potential turning point on one of the country's most divisive issues. High court review comes as the gay-marriage movement is showing unprecedented momentum, winning victories at the polls in four states this year.
The California dispute will address whether gay marriage is legal in the most populous U.S. state, home to more than 37 million people. The case also gives the justices a chance to go much further and tackle the biggest issue: whether the Constitution guarantees same-sex marriage rights nationwide.
That question is "perhaps the most important remaining civil rights issue of our time," said Theodore Olson, a Washington lawyer leading the fight against the California measure.
In addition to the California case, the justices Friday said they will review the U.S. Defense of Marriage Act, a 1996 law that two federal appeals courts said impermissibly treats legally married gay couples differently than heterosexual couples.
DOMA, as the measure is known, blocks gay people from claiming the same federal tax breaks and other marriage benefits that opposite-sex spouses enjoy.
Voters on Nov. 6 approved gay marriage in Washington state, Maryland and Maine, and rejected a bid in Minnesota to amend the state constitution to bar the practice. By Jan. 1, same-sex couples will have the right to marry in nine states, including New York, and the District of Columbia, and President Barack Obama has said he backs that right.
California voters approved Proposition 8, banning gay marriages, in 2008. The ballot initiative reversed a decision by the California Supreme Court, which five months earlier had said the state constitution guaranteed the right to gay marriage.
Supporters of the law say it promotes traditional marriage, and by extension makes it more likely that children will grow up in a nurturing environment.
Previous Supreme Court cases provide few hints as to how the court will rule. Although Justice Anthony Kennedy, who may cast the deciding vote, backed gay rights in 1996 and 2003 rulings, neither case involved marriage.
The court will review DOMA using the case of 83-year-old New York City resident Edie Windsor, who is fighting a $363,000 estate tax bill imposed after the 2009 death of her spouse, Thea Clara Spyer. Windsor and Spyer were married in Canada in 2007, a marriage the 2nd Circuit concluded would be recognized under New York law.
The battle over DOMA doesn't affect a separate provision in the law that says states can refuse to recognize same-sex marriages from other jurisdictions.