Darline Graham faces make-or-break GOP runoff in historic bid to keep brother’s Senate seat

President Donald Trump isn't on the ballot, but his clout over the GOP and the immense power of his endorsements in Republican primaries are on the line Tuesday in statewide runoff elections in South Carolina and Oklahoma.

Trump is backing Sen. Darline Graham in the Republican Senate nomination runoff in South Carolina, in the race to succeed her late brother, GOP Sen. Lindsey Graham, who unexpectedly died this summer at age 71.

And the president is supporting former state budget secretary and former state Sen.