Politico won’t say if a rival campaign fed them the story about sexual harassment allegations made against current Republican presidential front-runner Herman Cain in the 1990s. CNN’s Wolf Blitzer on Monday pressed reporter Ken Vogel of Politico on whether the publication relied on opposition research from one of Cain’s rivals. “Politics are politics as you said, and certainly there are people that are digging up opposition research,” Vogel said. “I’m just not going to do anything that would identify — that would point to the identity of our original source.” “We don’t think that the original source is as important...