president just like he was. >> you're a damn liar, man. that's not true, and no one has ever said that. no one has said my song has done anything wrong, and i did not on any occasion, and no one has ever said it -- >> i didn't say you were doing anything wrong. >> you said i set up my son to work in an oil company. isn't that what you said? get your words straight, jack. >> that was former vice president joe biden in a heated exchange. he was at a town hall in iowa thursday on his no malarky bus tour. while biden was sparring with a voter, other democrats were at each other. senator elizabeth warren attacked mayor pete buttigieg who has been rising in recent polls. when asked about a "new york times" editorial looking into the south bend mayor's past career with a consulting firm, she questioned his private