For many a baby-boomer, the sights and sounds of student protests against U.S. complicity in Israel’s war in Gaza brought back vivid memories of the anti–Vietnam War movement of their youth and of the conservative backlash that ultimately placed its legacy in question. Some of today’s protestors consciously promote an identification with their forebears of the 1960s and 1970s. And some events — notably the huge deployments of NYPD officers at Columbia...