A Billings group has joined those seeking the resignation of U.S. District Judge Richard Cebull over an email he forwarded that included a racist joke involving bestiality and President Barack Obama's mother.

The latest denunciation of the judge's conduct came as about 50 people gathered Tuesday night for a town hall meeting organized by Not in Our Town Billings.

Cebull apologized after acknowledging he forwarded the email to friends from his office computer in February. He also invited a review of his conduct by the 9th U.S. Circuit Court of Appeals.

That has not satisfied critics calling for his resignation, including the anti-racism group Not In Our Town. The legislature of the Crow Tribe and the good governance group Common Cause also have called for Cebull to step down.