Former Supreme Court Justice Sandra Day O'Connor on Wednesday said that it was "unfortunate" that some Republicans had called Chief Justice John Roberts a traitor to conservatives after he voted to uphold President Barack Obama's health care reform law.

During a Senate Judiciary Committee hearing on civics education, Chairman Patrick Leahy (D-VT) noted that attacks on judges could be a "threat to judicial independence."

"I am concerned about some of the rhetoric about the chief justice," Leahy told O'Connor. "He's been called everything from a traitor to having betrayed President George W. Bush."

"It's unfortunate," O'Connor agreed. "Because I think comments like that demonstrate only too well a lack of understanding that some of our citizens have about the role of the judicial branch."

"I think the framers of our federal Constitution did a great job in understanding themselves that the judicial branch needed to be able to make independent decisions and the legitimacy -- the lawfulness -- of actions at the state and federal lever," she added.