Protests at The New School, where a student uprising over the leadership of the university’s president, Bob Kerrey, led to clashes with the police and at least one arrest on Thursday morning, took another wild turn later on Thursday evening. A little after 11:30 p.m., Mr. Kerrey emerged from a university building on Fifth Avenue south of 14th Street to a sea of a few hundred protesters chanting for his resignation. As Mr. Kerrey walked down Fifth Avenue toward 12th Street, about 30 protesters began following him, some of them shouting insults. As the crowd’s pace quickened, so did Mr....