Sanford is the former Governor of South Carolina, who resigned after disappearing and then reappearing as an adulterer with an Argentine girlfriend. That woman — Maria Belen Chapur — is now said to be his "fiancée," and she was at his side for his victory speech last night. I put "fiancée" in quotes because he's trying to get back in the public's good graces, so he should have actually married her by now.
Sanford will now face Elizabeth Colbert Busch and Green Party candidate Eugene Platt in a May special election. She is the sister of political satirist Stephen Colbert.