Tamir Kalifa / The New York TimesHuyler Marsh, 21, is an accounting student at the University of Texas in Austin. A new “campus-carry” law has turned UT’s campus into a microcosm of the national debate over guns. “I wear it pretty much whenever I can,” Marsh said of his firearm. “It’s not that I’m afraid of getting attacked all the time. It’s more like a fire extinguisher or a seatbelt.”