Sen. Darline Graham secured the Republican nomination to replace her late brother Lindsey Graham on South Carolina's general election ballot, defeating Rep. Ralph Norman in Tuesday's GOP Senate primary runoff. The race became a high-profile test of President Donald Trump's endorsement power after he backed Graham in the final days of the campaign.

Graham thanked Trump and South Carolina voters Tuesday evening after NBC News and The Associated Press projected her victory. The win came despite a recent debate gaffe that threatened to derail her campaign. MAGA Inc., Trump's super PAC, spent $827,000 to back Graham on the final day of the runoff, according to the Associated Press.

Trump's Late Stage Intervention

The president's endorsement proved decisive in the homestretch. Gov. Henry McMaster joined Graham at a Monday news conference in Columbia, adding establishment Republican support to Trump's backing. The coordinated show of force came as Graham worked to distance herself from Norman's challenge and frame the race as a referendum on Trump's agenda.

Graham was initially appointed to fill the vacancy created by Sen. Lindsey Graham's sudden death in July at age 71. She is the first woman to serve as a U.S. senator from South Carolina. The appointment was widely viewed as an interim solution pending the primary outcome, but her victory Tuesday positions her as the heavy favorite in the deep-red state.

Norman Campaign Falls Short

Norman, a five-term House member representing South Carolina's 5th District, advanced to the runoff after the initial August primary, where Graham captured 32.6 percent of the vote to Norman's 24.1 percent. Anti-abortion groups backed Norman over Graham during the race, according to The Washington Examiner, attempting to frame the contest around social conservative credentials.

The runoff contest attracted national attention as one of several 2026 Republican primaries where Trump tested his influence over the party. Norman attempted to position himself as the more conservative alternative, but Trump's endorsement effectively neutralized that argument in the eyes of primary voters.

General Election Outlook

Graham now faces the Democratic nominee in November in what is expected to be a safe Republican seat. South Carolina has not elected a Democrat to the U.S. Senate since Fritz Hollings won reelection in 1998. Her brother held the seat since 2003, establishing a political brand that Graham sought to inherit during the primary campaign.

The race marks another Trump-backed candidate prevailing in a contested Republican primary, reinforcing the president's grip on GOP nomination contests heading into the fall midterm elections. Graham's win also ensures continuity in South Carolina's Senate delegation, where she will serve alongside senior Sen. Tim Scott.