U.S. Sen. Darline Graham won the Republican nomination to replace her late brother on South Carolina's general election ballot, notching another win for President Donald Trump after he threw his support behind the political novice.

The two-week runoff window since the two Republicans were the top vote-getters in an Aug. 11 primary has been a slugfest.

South Carolina Republicans will return to the polls Tuesday for the fourth time since June to replace the late U.S. Sen. Lindsey Graham on the fall general election ballot.