Under normal circumstances, Senator Darline Graham should not have won the Republican primary to replace her late brother, Senator Lindsey Graham. But then President Donald Trump stepped in. Graham scored a clear win in South Carolina Tuesday night. With 99 per cent of the vote counted, Graham had 52.5 percent of the vote over Representative Ralph Norman with 47.6 percent, according to The Associated Press. Her political fortunes had looked rocky ahead of Tuesday’s runoff during a debate with Norman, when she was asked about the South China Sea and Taiwan. Her late brother — a China and Russia hawk who had visited Ukraine shortly before his sudden death last month — would have argued that defending them was vital to American interests.Instead, his little sister said simply: “I’m not that informed on national security.”The gaffe was also a black eye for Trump, who had passed over a surefire candidate to endorse Graham as her brother's successor — first to finish out Lindsey Graham's term, then to serve a full term of her own.MAGA Inc., the super PAC affiliated with Trump, poured money into the primary, and the president traveled to Myrtle Beach to campaign with Graham last Friday.U.S. Senator Darline Graham (R-SC) gestures while speaking with supporters after winning her Republican primary runoff against U.S. Representative Ralph Norman (R-SC) for her current U.S. Senate seat, in Columbia, South Carolina, U.S., August 25, 2026. REUTERS/Sam Wolfe (Reuters)The gamble paid off.Trump has been particularly sensitive about his endorsement track record as of late. Earlier this week, he pushed back against the idea that he had lost his winning touch. “My Endorsements are stronger than ever — Not to mention the fact that good people are getting elected who never had the chance!” he insisted on Truth Social.In the past, the nod from Trump used to be a lock. His endorsements of Ron DeSantis in Florida and Brian Kemp in Georgia catapulted them to become governors of their states in the 2018 midterms. In 2022, JD Vance was languishing behind other Republican candidates for Senate before Trump gave his imprimatur, which set Vance on the course to be Ohio’s senator and ultimately, Trump’s vice president. That same year, he endorsed TV doctor Mehmet Oz, helping him become the Republican nominee for Senate in Pennsylvania. Trump cleared the field in the 2022 Georgia Senate race for Herschel Walker, and in Arizona, he backed Blake Masters for Senate.Trump backed a series of MAGA-aligned candidates in 2022 such as Mehmet Oz in Pennsylvania’s Senate race. Almost all of them fell flat. (AFP/Getty)But the last three fell flat. More recently, Trump’s endorsement has failed to do the trick elsewhere. In Georgia, he backed Lt. Gov. Burt Jones to succeed Kemp as governor, only for him to lose to Rick Jackson. He offered a last-minute endorsement to Rep. Randy Feenstra in Iowa in the primary for governor. But Feenstra lost to Zach Lahn. Earlier this year in South Carolina, he endorsed Lt. Gov Pamela Evette to be governor. But Trump would then double-endorse Evette and Attorney General Alan Wilson before the runoff to save face. The president had less-than-stellar luck in the Minnesota gubernatorial primary when Mike Lindell lost and Minnesota Republicans criticized Trump’s endorsement. He also whiffed his endorsement of Megan Degenfelder to be governor of Wyoming. Republican Rep. Andy Ogles lost his primary in Tennessee’s 5th district despite Trump’s endorsement (Getty)He also struck out recently in congressional endorsements. In Tennessee, he endorsed Rep. Andy Ogles, a firebrand with a history of Islamophobic and bigoted remarks who would lose to a more mainstream Republican named Charlie Hatcher. Trump endorsed Catalina Lauf, who would place second in Florida’s 19th district. And Representative Cory Mills, whom Trump also endorsed, lost his primary as he faces a House Ethics Committee investigation into whether he violated campaign finance law, misused congressional resources and whether he engaged in dating violence or sexual misconduct. Trump would subsequently try to wash his hands of Mills despite the endorsement. “I told Congressman Cory Mills of Florida, a friend of mine, to get out of the Race, but he wouldn’t listen. He thought he could win, so who can blame him?” he said.Trump still has the ability to motivate crowds - but seems to know that his voters are low-propensity.“They say that Trump does great when he’s on the ballot, but when he’s not on the ballot, his people don’t come and they don’t vote for senators, congressmen and other Republicans,” he told the South Carolina crowd who had turned out to see him campaign for Graham. “So what I really want you to do is pretend, please, that I’m on the ballot. Just come and vote.”What’s more, the president doesn’t not seem all that motivated to save his majority in Congress. Save for an event in Georgia and another in Michigan, Trump has not barnstormed swing states for his political allies the way he did in the 2018 midterms. His allies have not deployed MAGA Inc., which has roughly $400 million in cash to save endangered Republicans. Even in Texas, where his endorsement of Attorney General Ken Paxton saddled Republicans with a vulnerable candidate, Trump has mostly sat on his hands. Rather than focus on the long-term health of the GOP after he leaves office, Trump seems consumed with refurbishing Washington monuments, construction projects and trying to find a way out of the Iran war.And that might keep him from holding onto a majority that can insulate him politically in his final two years in the White House.