Trump's Endorsement Power Tested in South Carolina Senate Runoff

South Carolina Republicans headed to the polls on August 25, 2026, in a high-stakes special primary runoff that doubles as a referendum on President Trump's endorsement clout. At the center of the race: Darline Graham, the younger sister of the late Senator Lindsey Graham, who died suddenly in July 2026 leaving more than $2.3 million in his campaign account. Darline was appointed to fill the seat and is now running for a full six-year term, backed heavily by Trump and his super PAC MAGA Inc., which spent over $820,000 on her behalf. Trump personally campaigned in Myrtle Beach just the week before the vote.

Her opponent is Representative Ralph Norman, a hard-line conservative who has positioned himself as the experienced, substantive alternative. Norman's supporters repeatedly used the word 'nepotism' to describe Graham's candidacy, and Republican Party insiders in South Carolina largely expected Norman to prevail — particularly after Graham stumbled visibly in a debate the previous week. Norman drew backing from congressional Republicans in Washington and ran strongly in upstate areas like Greenville County, the largest source of GOP votes in the state.

The geographic fault lines were sharp: Graham performed well in metro areas like Columbia and Charleston and in Midlands counties near the Georgia border, while Norman dominated the conservative upstate. A late endorsement from Representative Russell Fry gave Graham a potential boost in fast-growing Horry County and the Myrtle Beach area, where Trump's loyalty ran deep — but where his prior endorsee, Lieutenant Governor Pamela Evette, had already lost a gubernatorial runoff earlier in 2026 despite his backing.

Turnout was unusually robust for a runoff. By 4 p.m., more than 280,000 ballots had been cast, on track to match or exceed the roughly 336,000 who voted in the initial primary two weeks prior. With only 1% of votes reported as of early evening, Graham held a 64%-36% lead over Norman. Oklahoma was simultaneously holding Republican primary runoffs for governor — pitting incumbent Gentner Drummond against Mike Mazzei, with a proposed $4 billion aluminum smelter in Inola as a key dividing issue — and for U.S. Senate.

The outcome carried outsized significance beyond South Carolina: a Graham loss would make her the first Senate candidate Trump endorsed in 2026 to be defeated, raising fresh questions about whether his political capital is eroding heading into the November midterms.