NEW HAVEN, Conn. (AP) -- Yale University's leaders on Saturday urged a campus conversation about whether to change the name of a residential college named for 19th century alumnus John C. Calhoun, a U.S. vice president and senator from South Carolina who was an ardent supporter of slavery. Debate over the name began this summer with a petition circulated after nine black worshippers were slain in a Charleston, South Carolina, church.