Former South Carolina Gov. Mark Sanford (R) is likely to run for Rep. Tim Scott's (R-S.C.) seat when Scott moves to the Senate.

"He's looking all but certain to do it," a former top aide to Sanford told CNN under condition of anonymity.

Sanford was once a rising star within the GOP — but ended his gubernatorial term amid scandal after he admitted to a longtime extramarital affair after disappearing for days from the state capitol. He is now divorced, and engaged to the woman with whom he had the affair.

Before his two stints as governor, he was the congressman from the Charleston, S.C. area — the same district Scott now holds. Scott will be appointed to the Senate to replace outgoing Sen. Jim DeMint (R-S.C.) sometime in the new year, and a GOP primary special election to replace him is expected to occur in March.

Sanford is likely to have company in the race — the heavily Republican district is already attracting the attention of a number of other local Republicans, including his ex-wife Jenny, who previously  said she hasn't ruled out a bid.