At a debate last night, Haley, who has repeatedly said she has been faithful for her husband of over a decade, said of Marchant's claim: "It never happened."
The AP has more:
He said he decided to go public after old rumors about a liaison were rekindled by Folks' claims.
"I did not have any intention of going public," Marchant said. "I kept getting calls from different people. I just felt like I owed Andre to disclose it to him. I did not do it until two days after I disclosed it to my wife."
Marchant said part of the reason he came forward was Haley's categorical denial last week of being unfaithful to her husband.
"It just gnawed at me to the point I had to confide in my wife and then we both made a joint decision that I was not going to push the issue but that if I was confronted, I was not going to lie about it," Marchant said.
Bauer asked Marchant to resigned from his campaign after a reporter made inquiries about the affair this week, according to the AP. The campaign cited "inappropriate conduct not in keeping with the goals of this campaign."
Marchant is described by the AP as "a well-known lobbyist who has led efforts to pass school choice legislation in South Carolina." He is president of the Palmetto Policy Group, where his bio says he was a staffer for Rep. Carroll Campbell. He has worked for the state Chamber of Commerce and the insurance industry.
Also worth noting is that just yesterday Haley released an ad referencing "the dark side" of politics and prominently featuring her husband Michael.
Late Update: Marchant describes what happened in his own words (video).