Trump-backed Republican defeats Rep. Mark Sanford, a conservative who has frequently criticized the president, in S.C. Primary. Sanford, a Republican who represents South Carolina’s 1st Congressional District, lost his primary race Wednesday to state Rep. Katie Arrington. Less than three hours before polls closed Tuesday, Arrington, a Trump ally, was rewarded for her loyalty with a tweeted endorsement from the president, who said Sanford was “very unhelpful” and “nothing but trouble.” Sanford is now the second incumbent Republican to lose his primary race this cycle, joining Rep. Robert Pittenger in North Carolina. Ref. USAToday.