The U.S. Court of Appeals for the Sixth Circuit upheld gay marriage bans in Michigan, Ohio, Kentucky, and Tennessee, setting the stage for what could be a Supreme Court showdown that could make the practice legal in all 50 states.

The 2-1 decision was the first legal setback for gay marriage advocates in federal court and creates a split among the nation's circuit courts.  In these sorts of disagreements, the Supreme Court usually steps in with a definitive ruling.

USA Today:

More important, it gives Supreme Court justices an appellate ruling that runs counter to four others from the 4th, 7th, 9th and 10th circuits. Those rulings struck down same-sex marriage bans in Virginia, Indiana, Wisconsin, Oklahoma, Utah, Idaho and Nevada, leading to similar action in neighboring states.

Circuit Judge Jeffrey Sutton, one of the Republican Party's most esteemed legal thinkers and writers, issued the 42-page decision precisely three months after hearing oral arguments in the cases, with fellow GOP nominee Deborah Cook concurring. He delivered a rare defeat for proponents of same-sex marriage, who had won nearly all the cases decided from Florida to Alaska since the Supreme Court ruled against the federal Defense of Marriage Act in June 2013.

Sutton argued that appellate judges' hands are tied by a one-sentence Supreme Court ruling from 1972, which "upheld the right of the people of a state to define marriage as they see it." Last year's high court decision requiring the federal government to recognize legal same-sex marriages does not negate the earlier ruling as it applies to states where gay marriage is not legal, he said. The same reasoning was used by a federal district court judge in Puerto Rico last month.

"When the courts do not let the people resolve new social issues like this one, they perpetuate the idea that the heroes in these change events are judges and lawyers," Sutton said. "Better in this instance, we think, to allow change through the customary political processes, in which the people, gay and straight alike, become the heroes of their own stories by meeting each other not as adversaries in a court system but as fellow citizens seeking to resolve a new social issue in a fair-minded way."

He also maintained that states "got into the business of defining marriage, and remain in the business of defining marriage, not to regulate love but to regulate sex, most especially the intended and unintended effects of male-female intercourse."

This has been the argument all along: who defines marriage?  The courts or state legislatures?  To date, only 7 state legislatures have given the go-ahead to gay marriage.  In all other states where it is legal, the decision came from a federal judge.  This monumental change in the culture needs to be addressed by the people, not a judge who applies his own narrow ideology to the decision.  If that means that gay marriage is delayed for some, it's a small price to pay in order to change the culture the right way.

But it's probably too late to stop it.  With gay marriage legal in 32 states, a definitive ruling legalizing it in all 50 states is inevitable.  If the Supreme Court has been looking to make a definitive ruling on the issue, this would appear to be the opportunity they've been waiting for.