South Carolina Gov. Mark Sanford, who was thought to be a possible Republican presidential candidate in 2012, admitted to an extramarital affair today with a woman in Argentina, and resigned as chairman of the Republican Governors Association.

"I've been unfaithful to my wife," Sanford said to explain his whereabouts for the past few days.

"There are moral absolutes, that God's law indeed is there to protect you from yourself, and there are consequences if you breach that. This press conference is a consequence."

Sanford apologized profusely both to family members and staff for his actions, and asked for forgiveness.

"I hurt my wife, I hurt my boys, I hurt a lot of different folks," he said. "I've let down a lot of people, that's the bottom line."

When asked by a reporter if he and his wife were separated, Sanford responded, "I'm here and she's there. I guess in a formal sense we're not."

The governor indicated his family was aware of the affair before he left on what he called an adventure trip last Thursday.

"We've been working through this thing for about the last five months," he explained. "What I did was wrong, period."

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Questions had been swirling across the country since Monday when headlines emerged asking, "Where is Gov. Mark Sanford?"

His wife, Jenny, reportedly said she did not know her husbands whereabouts, and staff had told reporters that he was on a hiking trip along the Appalachian Trail. Before today's revelation of what really took place, even radio host Rush Limbaugh was downplaying the news coverage.

"So what?" said Limbaugh. "A governor takes five days off. Big whoop. How many lives changed?"

Sanford apologized to his staff for misleading them about his whereabouts, saying: "I want to make absolutely clear that over the past two days at no time did anyone on my staff intentionally relay false information to other state officials or the public at large. What they've said over the past two days they believed to be true, and I'm sorry to them for putting them in this position."

A statement from Jenny Sanford indicates she asked her husband to leave the family two weeks ago:

When I found out about my husband's infidelity I worked immediately to first seek reconciliation through forgiveness, and then to work diligently to repair our marriage. We reached a point where I felt it was important to look my sons in the eyes and maintain my dignity, self-respect, and my basic sense of right and wrong. I therefore asked my husband to leave two weeks ago.

This trial separation was agreed to with the goal of ultimately strengthening our marriage. During this short separation it was agreed that Mark would not contact us. I kept this separation quiet out of respect of his public office and reputation, and in hopes of keeping our children from just this type of public exposure. Because of this separation, I did not know where he was in the past week.

Mrs. Sanford added that "Mark has earned a chance to resurrect our marriage" and she remains "willing to forgive Mark completely for his indiscretions and to welcome him back, in time, if he continues to work toward reconciliation with a true spirit of humility and repentance."

Regarding the governor's love interest in South America, Mark Sanford said: "I started a relationship with what started as a dear, dear friend from Argentina."

He explained it commenced in 2001, and grew with time, finally becoming romantic in the past year.

"It began just on a very casual basis," he said. "We developed  a remarkable friendship over those eight years."

Sanford said he felt because of the geographical distance between the pair, "There was this zone of protectedness."

But he added, "When you live in the zone of politics, you can't ever let your guard down."

He stated there was "a certain irony in this," because as the relationship was beginning, he had a discussion with her "about why she should get back with her husband."

"I've seen her three times since then, since the whole sparking thing."

Many watching Sanford's announcement expressed outright shock to the news.

"This is a tremendous blow to us right now," Katon Dawson, said former chairman of South Carolina's Republican Party, but added, "We'll work through this."

"This is a blockbuster to the Grand Ole Party," noted Fox News anchor Trace Gallagher.

"Somewhere right now Mitt Romney is smiling," responded political analyst Bill Sammon. "[Sanford] has damaged himself now. I'd be surprised to see him come back from this."

While Sanford announced his resignation as chairman of the Republican Governors Association, he did not hint about stepping down from his role as head of South Carolina. Mississippi Gov. Haley Barbour was quickly named as Sanford's replacement at the RGA.

Related story:

Jenny Sanford: I asked husband to leave 2 weeks ago