Cain: We have ‘no idea’ who fed Politico the sexual harassment story

Republican presidential candidate Herman Cain, responding to a recent Politico story that included anonymous charges of sexual harassment while he was chairman of the National Restaurant Association in the 1990s, said he has "no idea" who fed the press the story.

"We have no idea about the source of this witch hunt," Cain said during a speech at the National Press Club Monday.

Cain Campaign Manager Mark Block told reporters he didn't think the story came from one of his rivals, but left the possibility open.

"I find it hard to believe that anybody from another campaign would do that," Block said. "But this is politics, isn't it?"

Cain spent much of his day Monday addressing the charges in the story, which he called "totally false," although he affirmed that allegations were made and an investigation found no wrong doing. At least one of his accusers received a settlement, according to an NBC News report.