Washington DC - Darline Graham, the sister of late Senator Lindsey Graham, has advanced to a runoff in the Republican South Carolina Senate primary to fill his seat.
With roughly 85% of ballots counted on Tuesday night, Graham advanced to a runoff with 33% of the vote against Congressman Ralph Norman, who was projected to finish second at 24%.
The runoff is slated for August 25, and the winner will go on to face Democrat Annie Andrews in November.
Graham faced a crowded field that included Norman, Congressman Russell Fry, and former Governor Mark Sanford.
The 62-year-old was appointed to fill her brother's Senate seat last month after his death at the age of 71 due to a "sudden illness."
Lindsey Graham had been a vocal critic of President Donald Trump before becoming a key ally in Congress up until his passing.
The president had recommended Darline Graham to become Lindsey's temporary replacement shortly after his death and went on to fervently endorse her in the primary.
Trump even held a telephone rally for Graham on Monday, calling her the "perfect person" to carry on her brother's legacy, but rivals have attacked her lack of political experience and argued that she inherited her position rather than earned it.
The South Carolina seat is safely Republican, limiting its importance for control of Congress.
On the Democratic side, several primaries across the US – including the closely watched Wisconsin gubernatorial race – put the party's leftward surge to the test on Tuesday night.