NEW : Judges ask tough voters to side with same - sex marriage . A panel of judges will hear arguments over whether the amendment is constitutional . A lengthy legal battle began after voters approved Proposition 8 . A federal judge 's earlier ruling says the proposition violates the Constitution .
NEW : Judges ask tough questions to side opposing same-sex marriage . A panel of judges will hear arguments over whether the measure is constitutional . A lengthy legal battle continues after voters approved Proposition 8 . A federal judge 's earlier ruling says the proposition violates the Constitution .