Former South Carolina Gov. Mark Sanford endorsed Rep. Ralph Norman over Sen. Darline Graham in the Republican primary runoff for the U.S. Senate on Friday.

Sanford, who finished fourth in the August 11 special primary with about 15 percent of the vote, said he typically avoids endorsements in such races but felt compelled to act. He pointed to Norman's record on government spending and the national debt as the deciding factors.

"The stakes are simply too high," Sanford stated in remarks shared on social media. Norman, he argued, holds the best shot at holding the line on spending, debt, and deficits.

The runoff pits Norman, a U.S. representative from the 5th District known for fiscal conservatism, against Graham, the sister of the late Sen. Lindsey Graham. She was appointed to finish her brother's term after his death on July 11 and received President Donald Trump's endorsement.

Norman advanced from the primary with strong support in the Upstate, while Graham carried much of the Lowcountry and Midlands. The winner will face Democrat Annie Andrews in the November general election.

Sanford's backing adds to endorsements Norman has received from other conservative lawmakers, including Sens. Rick Scott of Florida and Mike Lee of Utah. Analysts note that supporters of eliminated candidates like Sanford and Rep. Russell Fry could influence the outcome in the tight race.

Early voting for the runoff began Wednesday and continues through Friday, with Election Day set for Tuesday, August 25.

The contest has highlighted divisions within the South Carolina Republican Party over spending priorities and alignment with national conservative trends.