Judicial bias is a tricky thing. It shouldn't exist, of course—donning a black robe should confer superpowers that remove all traces of prejudice from the human mind.

But in the real world, it's not so simple. Which is why a complaint filed on Tuesday against a Kentucky judge by Lambda Legal, the American Civil Liberties Union, the ACLU of Kentucky, Kentucky's Fairness Campaign and University of Louisville Law Professor Sam Marcosson raises some difficult questions.

The civil rights groups are calling on Kentucky's Judicial Conduct Commission to remove family court Judge W. Mitchell Nance. The reason: Nance recused himself from all adoption proceedings involving lesbian, gay and bisexual people because he does not believe it is in the best interests of a child to be placed in such families.