In what became an emblematic scene, Rep. John Dingell (D-Mich.), faced a hostile crowd at a packed health care town hall in Michigan on Thursday. Dingell, a major sponsor of health care reform legislation, was repeatedly shouted down. At one point, a man named Mike Sola wheeled his son to the front of the room and engaged in a YouTube-bound shouting match (see below) with Dingell before being escorted out by police. But who was actually populating this angry mob?