Charleston, S.C.

As Sean Hannity stood onstage Friday with Ted Cruz before a packed audience at the College of Charleston's Sotille Theater, the Fox News host announced that "a few special guests" were backstage. "Moments before we came out here, you got a big endorsement," Hannity said. With less than 24 hours until the South Carolina GOP primary, Congressman Mark Sanford, the state's former governor, emerged from behind a velvet curtain.

The crowd went wild, and Sanford then spoke for one minute about why he was supporting Cruz. Sanford mentioned the importance of upholding the Constitution and how impressed he was that Cruz came out against ethanol subsidies in Iowa. "We need another fighter in Washington," Sanford said. He then slipped back behind the curtain.

It was an odd way to announce the endorsement of a former governor. Had the Cruz campaign deliberately waited until last minute to roll out the endorsement of Sanford, who resigned from his post as head of the Republican Governors Association in 2009 amid revelations of an affair?

According to a statement later released by Sanford, the former governor simply hadn't made up his mind to endorse anyone until he watched Donald Trump's CNN townhall interview Thursday night. "After watching a CNN town hall meeting last night and some of the responses that came from Mr. Trump I felt it was important to publicly state how I intended to vote tomorrow. As a consequence, I came out for Senator Cruz this afternoon," Sanford said. "It looks to me that he has the best chance of beating Mr. Trump, and I think it is important that someone does."

"To suggest that former President Bush was a conspirator in the 9/11 attacks is to flame all the conspiracy theories that undermine the very trust essential to representative government," Sanford added. "To dismiss the idea of entitlment reform at a time when balanced budgets cannot be achieved without it, is to pander to the worst degree."

Sanford's strange story seemed sincere. When I saw Sanford at a Marco Rubio event on Wednesday, he said: "I haven't endorsed in the race, I'm not going to endorse. I'm just spectating." Sanford did seem perplexed and disturbed that Trump was running away with the race. "I've run my share of statewide races over the years, but I can't figure this one out. It defies all political convention. The idea that Donald Trump would be leading in the evangelical belt of our state is sort of a non sequitur. It is not something I would have imagined. All I can figure is that people's frustration with Washington and the economy trumps even their normal biases in terms of civility."

Although Sanford's approval ratings took a big hit following the 2009 scandal that led to his resignation, he still has fans in the state. But his endorsement may have come too late for it to sway anyone.

Update: This article has been updated to clarify that Sanford resigned as head of the RGA, not from his role as governor.