WASHINGTON -- The U.S. Supreme Court may rule once and for all this year whether the constitutional guarantee of equal protection under the law gives gay and lesbian Americans the right to marry.

Meeting behind closed doors on Friday, the nine justices decided to review a 2-1 decision by the U.S. Court of Appeals for the 6th Circuit that upheld bans on same-sex marriage in Ohio, Michigan, Kentucky and Tennessee. The decision by two judges on the Cincinnati-based court, both appointed by President George W. Bush, marked the first time a federal appeals court backed a same-sex marriage ban after other appellate courts had found similar bans unconstitutional. That split among the circuit courts likely drove the justices to pick up the case.

The Supreme Court will hear arguments and probably rule by June.

The court said it would specifically address two questions: Does the 14th Amendment require a state to license a marriage between two people of the same sex? And does the 14th Amendment require a state to recognize a marriage between two people of the same sex when their marriage was lawfully licensed and performed out-of-state?

The justices also announced that oral argument in the case (actually four consolidated cases) will be longer than usual: 90 minutes for the first question and another 60 minutes for the second.

The decision to take up the case returns the justices to a path that began in 2013, when the high court struck down parts of the Defense of Marriage Act, ruling 5-4 that key provisions of the 1996 law that banned the federal government from recognizing same-sex marriages were unconstitutional. The same day, the court avoided ruling on the merits of a separate case questioning the constitutionality of state same-sex marriage bans, finding instead that a private party did not have standing to defend the California law in court.

Based largely on the decision in the DOMA case, written by Justice Anthony Kennedy, federal courts around the country began striking down same-sex marriage bans in several states. By October 2014, when the Supreme Court rejected appeals from five states that wanted to bar gay marriage, every federal appeals court that had addressed the issue had held same-sex marriage bans unconstitutional. As a result, Supreme Court justices evidently concluded they didn't need to address the issue.

The 6th Circuit's decision apparently changed justices' minds.

With the addition of Florida earlier this month, the 36 states and the District of Columbia that now allow gay marriage encompass 70 percent of the U.S. population.

The Supreme Court's decision to take up the case may expand marriage rights in the remaining 14 states. That's a conclusion that Justice Antonin Scalia, in his blistering dissent in the DOMA case in 2013, said was "inevitable."

When will we just revolt?