Open this photo in gallery: Demonstrators wave a Palestinian flag on the Columbia University campus in New York at a protest encampment on April 29.Ted Shaffrey/The Associated Press From Columbia in the east to UCLA in the west, American campuses are being roiled by chants and challenges to authority, protests and police presence – a burgeoning set of angry confrontations on college quadrangles that have revived a classic debate about the nature of free speech, the purpose of higher education and the role of a university in broader society. These questions are concentrated on the Gaza war, but they go...