Senator Darline Graham of South Carolina, who was sworn in last week to temporarily replace her brother, the late Senator Lindsey Graham, said on Monday that she would enter the race to succeed him.
The announcement came days after President Trump urged her to run for the seat. It cements her rapid transformation from a grieving sister seen as a caretaker of the Republican-held Senate seat to a first-time candidate vying for a place in the nation’s most powerful governing body.
Ms. Graham shared her decision in an interview with the Fox News host Sean Hannity.
“I feel like I can do it,” she said in a clip from the interview, which was shared on Monday. “I feel an inner peace about it.”
The filing period for the special Republican primary election opens on Tuesday and closes on July 28. The special election is scheduled for Aug. 11.
No one has been more central to Ms. Graham’s sudden rise than Mr. Trump, who has repeatedly intervened to elevate her since Mr. Graham, his longtime ally, died on July 11.
Shortly after Mr. Graham died, Mr. Trump posted on social media encouraging Gov. Henry McMaster of South Carolina to appoint Ms. Graham as an interim senator, saying that it would be “a fabulous tribute to Lindsey.” Days later, the president met with her in the Oval Office.
Then, on Friday, Mr. Trump publicly encouraged Ms. Graham to run for her brother’s seat.
“Darline, who comes from an absolutely incredible family, has been a WINNER all of her life and, should she accept, has my Complete and Total Endorsement in the Special Election for U.S. Senate in South Carolina,” Mr. Trump wrote on his social media site. “SHE WILL NEVER LET YOU DOWN. RUN, DARLINE, RUN!”
Several other prominent Republicans in the state, including Representatives Russell Fry and Ralph Norman, have already indicated their intentions to run.
Ms. Graham, 62, has worked in various jobs to help people with disabilities find work — including most recently as commissioner of a state agency for blind residents. She does not appear to have previous political experience, other than publicly supporting her brother’s career.
The siblings formed a particularly tight bond after losing both of their parents in a 15-month stretch, their mother to cancer and their father to a heart attack. Mr. Graham, 22 at the time, promised to care for his 13-year-old sister.
They remained close through the years.
On Monday, Senator John Thune of South Dakota, the Republican majority leader, called Ms. Graham a “strong candidate” but said he would not endorse a candidate in the race.
“She, obviously, carries on Lindsey’s legacy,” he said. “She’s a very accomplished person in her own right, and so she has a right like anybody else to get into that race.”
Michael Gold contributed reporting.
