They say they're still figuring out whether to ask the full Appeals Court to weigh in - instead of just the three-judge panel - or whether to go straight to the U.S. Supreme Court.
Matt McReynolds with the Pacific Justice Institute says each state's voters should have the right to decide whether same-sex marriage should be legal.
McReynolds: "If the voters genuinely want to expand the traditional definition of marriage, then we think that's the voters' right to do that. What we don't think is right is for it to be imposed by the judiciary."
A lawyer for Prop 8's official sponsor … protect-marriage-dot-com … says the Appeals Court's decision is "out of step" with other rulings on the issue of marriage.