Proposition 8 supporters faced tough questions in a California court Monday, as they challenged a homosexual judge's ruling to allow same-sex marriage in the state.

Attorneys defending Prop 8 say Judge Vaughn Walker's 2010 decision to overturn California's voter-approved gay marriage ban presented a conflict of interest, since he is gay himself.

They say he should have been recused from the case because of his long-term relationship with another man. Vaughn has since retired.

Monday, Prop 8 sponsors took their challenge before Chief U.S. District Judge James Ware, who's taken over since Vaughn's retirement. Ware is an African-American judge nominated by former President George H.W. Bush.

"If a reasonable person thought a black judge should recuse himself from a civil rights case, that would be sufficient to recuse the judge?" Ware asked.

"No, your honor," Prop 8 attorney Charles Cooper responded.

An attorney for the couple seeking to overturn Proposition 8 called the Vaughn challenge "frivolous."

Judge Ware said he would issue a written ruling on the case at a later date.

The main Proposition 8 lawsuit was appealed to the 9th U.S. Circuit Court of Appeals, and could reach the Supreme Court.