WASHINGTON (CNN) - Race and politics are a combustible combo that explodes into headlines when an ex-president lights the fuse, as Jimmy Carter did recently.
"When a radical fringe element of demonstrators and others begin to attack the president of the United States as an animal or as a reincarnation of Adolf Hitler or when they wave signs in the air that said we should have buried Obama with Kennedy, those kinds of things are beyond the bounds," the Democrat told students at Emory University on Wednesday.
"I think people who are guilty of that kind of personal attack against Obama have been influenced to a major degree by a belief that he should not be president because he happens to be African-American," he added.
The controversy erupted this week when Carter first raised the race issue to NBC.
"An overwhelming portion of the intensely demonstrated animosity toward President Obama is based on the fact that he is a black man," he said.
Bill Cosby, a black comedian and actor, said Wednesday in a written statement that he agrees with Carter.
"During President Obama's speech on the status of health care reform, some members of Congress engaged in a public display of disrespect," he said.
CNN contributor David Gergen said that some of the allegations of race-baiting might have some weight among Democratic voters.