WASHINGTON -- The Supreme Court turned to same-sex marriage Friday in a big way, by agreeing to review a California ballot measure that banned it and a federal law that blocks benefits for married same-sex couples.

In an ambitious move, the justices agreed to second-guess a lower court’s decision striking down California’s Proposition 8. Simultaneously, they agreed to consider challenges to the federal Defense of Marriage Act, which blocks same-sex married couples from receiving a host of federal benefits.

The separate cases, to be heard next year, will thrust the often-divided high court into hot political territory and tricky constitutional terrain.

It “tees up the fundamental question of whether the Constitution’s promise of equality for all persons applies to gay men and lesbians when it comes to marriage,” declared David Gans, the civil rights director of the Constitutional Accountability Center, which supports gay marriage.

Meeting in a private session Friday morning, justices had to pick and choose among 10 different appeals that deal in some fashion with same-sex marriage. Eight of the appeals cases challenged the federal Defense of Marriage Act. One appeal involved an Arizona law on benefits for state workers, and one dealt with California’s Proposition 8.

The justices’ action came a day after Maryland issued its first same-sex marriage licenses, after voters approved a ballot measure last month.

Advocates from both sides voiced confidence Friday that they’ll prevail once the court hears arguments, which could happen in March.

California Attorney General Kamala Harris, an opponent of Proposition 8, said the court’s decision to hear the case “takes our nation one step closer to realizing the American ideal of equal protection under the law for all people,” while National Organization for Marriage Chairman John Eastman called the decision “a strong signal” that the Supreme Court will reverse the lower courts and uphold Proposition 8.

At a dance club near California’s state Capitol building, a handful of same-sex marriage advocates, hoping the court would decline to hear the case, had waited for hours for the decision Friday and were crestfallen when it came. Ken Pierce, a spokesman for the Sacramento advocacy group Equality Action Now, lamented that “we’ve waited so long” for same-sex marriage to be upheld.

As is customary, the justices didn’t explain their decision about which cases to hear. No decision was announced on the Arizona case.

The California state ballot measure declared that “only marriage between a man and a woman is valid or recognized.” The state’s voters approved it in 2008 by 52-48 percent, casting into limbo the status of same-sex couples who’d already been married in the state. More than 18,000 same-sex marriage licenses were issued in California before the ballot measure passed.

In a narrowly written decision issued last February, the 9th U.S. Circuit Court of Appeals struck down Proposition 8 on the basis that it stripped individuals of rights that had previously been granted when gay marriages were permitted.

“Proposition 8 serves no purpose, and has no effect, other than to lessen the status and human dignity of gays and lesbians in California, and to officially reclassify their relationships and families as inferior to those of opposite-sex couples,” Judge Stephen Reinhardt wrote for the appellate court. “The Constitution simply does not allow for laws of this sort."