Sanford, a Republican, won 54 per cent of the vote, defeating Democratic candidate Elizabeth Colbert Busch, a sister of the political satirist Stephen Colbert, a host on the Comedy Central channel.
In 2009 Sanford's political career seemed to be over when he covered up a trip to Argentina to see his mistress, Maria Belen Chapur, a woman he later described as his "soul mate", by having his staff cover for him, saying he was hiking the Appalachian Trail, a hiking path in the eastern United States.
He and his wife, Jenny, were divorced in 2010 and he finished his second term as governor in 2011. The scandal ended any hopes of Sanford running for the 2012 Republican presidential nomination.
In 2010 he paid at the time the largest ethics fine in state history, penalties of $74,000 (€54,000), and $36,000 to cover investigation and other costs, arising from an ethics inquiry into his behaviour.
Many had believed that Sanford would end up in the political wilderness after the end of his controversial governorship.
In a victory speech following his victory in South Carolina’s first congressional district, Sanford described himself as “one imperfect man saved by God’s grace”. “I want to acknowledge a God not just of second chances but third, fourth, fifth, sixth, seventh, eighth chances because that is the reality of our shared humanity,” he said.
Chapur, now Sanford’s fiancee, and his son Marshall stood alongside him at the victory celebrations.
In a special election that had a very high turnout, Sanford won all five counties in the district including areas where Democrats had hoped that past controversies would put off older voters.
Sanford lost the support of the powerful Republican national congressional committee and his victory came in the face of strong national Democrat financial support for his opponent.
