Washington — South Carolina Gov. Henry McMaster is set to appoint the late Sen. Lindsey Graham’s sister Darline Graham Nordone to finish his Senate term, which ends in January, sources familiar with the decision tell CBS News. 

McMaster is holding a press conference at 4 p.m. to announce his appointment for the vacant seat left by Graham’s death. The replacement will be able to serve until at least Jan. 3, when a new Congress convenes.

President Trump, Sen. Tim Scott of South Carolina and others have voiced their support for Nordone. Senate Majority Leader John Thune told CNN that selecting Graham’s sister “makes a lot of sense.” 

 Graham took legal guardianship of his sister when he was 22 and she was 13, after both of their parents died within 15 months of each other.

Graham was also running for reelection this fall, and a special Republican primary election will be held on Aug. 11 to determine who will replace him on the ballot. The candidate who wins in November will secure a full six-year term. 

Graham died Saturday at the age of 71, and a medical examiner’s preliminary findings suggested the cause was aortic dissection, which involves a tear in the main artery from the heart.

Through the years, Nordone has been active in supporting Graham’s political ambitions, attending his political and official events. 

On Monday morning, Mr. Trump threw his endorsement behind Graham’s younger sister to serve the rest of his term. 

“I recommended, to Governor Henry McMaster, Lindsey Graham’s wonderful sister, Darline, to serve as interim Senator from the Great State of South Carolina,” Mr. Trump wrote on Truth Social. “This would be a fabulous tribute to Lindsey, who loved her dearly!”

Scott told “CBS Mornings” that Nordone “would be a wonderful placeholder.” Scott has spoken to Nordone multiple times over the past 24 hours, a source familiar with the talks told CBS News. Scott is expected to be on hand for the announcement later Monday, and the interim senator is set to be sworn in on Wednesday.