Obama campaign says Romney lying about involvement with Bain after he left . Romney campaign chief says Obama should apologize for ` ` out of Romney '' campaign . Several sources said that Fund VII was the main investment vehicle at that time . Four senators -- three of them Democrats -- support Romney out of dispute . Obama campaign wants to tie story to other attacks on Romney 's campaign .
Obama campaign says Romney lying about involvement with Bain after he left . Romney campaign chief says Obama should apologize for ` ` out of Romney '' campaign . Four senators -- three of them Democrats -- support Romney out of dispute . Obama campaign wants to tie story to other attacks on Romney 's campaign .