Charles P. Pierce of Esquire knows from ringers:
The real action at these rallies is on the fringes. (It should be noted that the entire Trump campaign consists of rallies like the one in Lowell. Well, that, and the endless free media he attracts.) The crowds are edged with a startling amount of security, both public and private. There were cops from several towns on duty in Lowell, and a remarkable number of people in suits, wearing earplugs, but not wearing any Secret Service insignia. By my count, the event was interrupted five times by protesters. The protesters were curiously able to infiltrate the tight security, and their conspicuous removal became an integral part of the show. Their expulsion never failed to give He, Trump another rhetorical launching pad for some of the high-flown, winking contempt he shares for the Other with his crowd. It is what binds them to each other. “Get them out,” he says, and everybody cheers.