"I think it's based on racism. There is an inherent feeling among many in this country that an African-American should not be president." The Georgia Democrat said the outburst was a part of a disturbing trend directed at the president that has included demonstrators equating Obama to Nazi leaders. "Those kind of things are not just casual outcomes of a sincere debate on whether we should have a national program on health care," he said. "It's deeper than that."