Headline: Thune says his endorsement 'probably isn't helpful' in race to replace Lindsey Graham Lead: Senate Majority Leader John Thune (R-SD) questioned the effectiveness of his endorsement power Tuesday in South Carolina's special GOP Senate primary to replace the late Sen. Lindsey Graham. "My endorsement probably isn't helpful anyway to anyone that's running in the primary right now." "She's obviously made the decision. The president's endorsed her." Thune "declined to join President Donald Trump and much of the Senate GOP leadership in endorsing Graham Nordone." He called her a "strong candidate." Mark Lynch lost to Lindsey Graham in the initial June primary "by nearly 28 points."