Former South Carolina governor Mark Sanford (R) addressed his dramatic 2009 fall from grace at a debate Thursday night, saying he failed in a very public way but emerged with humility that would serve him well in Congress.

"My faults are out and they are exposed," Sanford said. "But all I can say is that I have learned mightily from every one of those mistakes."

After disappearing from the state for nearly a week as governor in 2009, Sanford revealed an extramarital affair, a stunning admission for the onetime rising GOP star. He served out the remainder of his term and is now trying to win back the 1st district congressional seat he once held.