Democratic members of North Carolina’s congressional delegation are asking the U.S. attorney general to investigate a South Carolina sheriff’s office weeks after a bus full of Shaw University students was stopped and searched on the way to Georgia. A group of 18 students and two advisers were on their way to a conference in Atlanta Oct. 5 when Spartanburg County sheriff’s deputies pulled over the group’s chartered bus. Shaw University President Paulette Dillard said in a statement that the stop was prompted by a “minor traffic violation” and that drug-sniffing dogs searched through riders’ lug…