Graham was up for re-election in 2026. Annie Andrews (D) won the S.C. Democratic Senate primary, and was set to run against the winner of the Republican Senate primary, Graham (R). Governor McMaster will have to call for a special primary to elect a Republican nominee to run against Andrews in the general election.

Edited to add: The deadline to hold a special primary is August 11. Republicans don't have much time to choose their Senate candidate.

Rec

Haley defeated McMaster in the Republican primary for S.C. Governor in 2010. Haley and McMaster were on opposite sides of various important issues during the primary, they were not close politically. McMaster was then elected as Lieutenant Governor of South Carolina in 2014, and served in that position until 2017 when he replaced Haley after she resigned. McMaster has since been re-elected twice as S.C. Governor.

I've read (an opinion from an unidentified source) that Trump doesn't want her appointed to Graham's seat, and Haley isn't interested.

Repubs had 53 seats, Democrats 45 and Independents, voting with Democrats, 2.

There were 53 Republicans.

So still a working majority for the repubs.