COLUMBIA, S.C. (AP) — U.S. Sen. Darline Graham and U.S. Rep. Ralph Norman face South Carolina voters yet again Tuesday in a special Republican primary runoff to replace the late Lindsey Graham in the Senate, one month after his sudden death.The two-week runoff window since the two Republicans were the top vote getters in an Aug. 11 primary has been a slugfest. Darline Graham — a political newcomer serving as interim replacement for her late brother — has struggled to define herself to voters who routinely backed Lindsey Graham in the heavily Republican state. Norman, who’s served the better part of two decades in state and federal elected office, has stressed his experience to voters already aware of him from his years in Congress, plus an unsuccessful run for governor earlier this year.In the background of all of this is President Donald Trump, the longtime Lindsey Graham ally who endorsed Darline Graham’s candidacy to replace her brother in the November general election before she even entered the race, stumped for her in the state days ahead of the runoff and held a runoff-eve tele-rally with Graham. On Monday, MAGA Inc., the super PAC that supports Trump and aligned Republicans — but has spent little thus far on Trump’s picks in this year’s midterms — infused nearly $830,000 into Graham’s campaign for voter calls and text message blasts.Among the unknowns are if Trump’s backing is enough to boost the novice candidate with the famous last name, but whose political positions were previously unknown, across the finish line to the nomination. Also yet to be determined is if Norman’s hard-line conservatism has an appeal statewide, two months after he finished third in the Republican governor’s primary.