(CNN) - Attorneys on both sides of the same-sex marriage debate faced off Monday in a federal appeals court in California, as a panel of judges heard arguments about the constitutionality of Proposition 8.
In August, a federal judge ruled that the voter-approved measure, which defined marriage as a union between a man and a woman, violated the U.S. Constitution. The Ninth U.S. Circuit Court of Appeals considered an appeal of that judge's ruling Monday.
The three-judge panel opened Monday's hearing with tough questioning of parties seeking to appeal the decision, including ProtectMarriage.com and Isabel Vargas, who's a deputy clerk and deputy commissioner of civil marriages for Imperial County, California, where voters overwhelmingly approved Proposition 8.