South Carolina Gov. Mark Sanford held a press conference this afternoon where he admitted what we already knew: He didn't really go hiking on the Appalachian Trail over Father's Day weekend when questions arose about his whereabouts.

Instead, he was in Argentina -- ending an affair with a friend that began about a year ago.

The press conference, scheduled for 2 p.m., began about a half hour late. When Sanford came to the podium, he began by talking about a conversation he had had with a reporter this morning in which he told her about his love of the Appalachian trail and adventure travel.

"What I found in this job is that one desperately needs a break from the bubble, when every word, every moment is recorded," he said.

He went on to discuss the "profound frustrations" he felt during the recent legislative battle over the federal stimulus package, funding from which he wanted to reject. He denied that his actions were part of any quest for a higher political office but based on his belief that accepting the money would be bad for taxpayers.

Sanford then apologized to his wife, Jenny; their four sons; his staff; the people of South Carolina; his friends; and his parents-in-law. He talked about how forgiveness is not immediate but rather a process that takes time. He also talked about what he called "God's laws" and how they aim to protect people for themselves, and he apologized to "people of faith across South Carolina and across the nation."

Then the governor finally cut to the chase.

"I've been unfaithful to my wife," he said. "I developed a relationship with somebody who started as a dear, dear friend from Argentina."

Sanford never mentioned the woman's name, saying only that their relationship began innocently about eight years ago, and "developed into something more" about a year ago. He said the affair "was discovered" five months ago.

Sanford noted that there was a "certain irony" in the way they became friends: At the time the woman was separated from her husband, and Sanford counseled her about why it was important for her to return to the marriage for the sake of her children.

In the interest of time, Sanford said, he would resign as chair of the Republican Governors Association. Gov. Haley Barbour of Mississippi serves as the organization's vice chair.

Sanford said that he and his wife were already in the process of reconciliation and asked for a "zone of privacy" for his family.

"I spent the last five days of my life crying in Argentina," he said. "I'm committed to trying to get my heart right."

As Pam Spaulding observes over at Pam's House Blend, there's more than a little hypocrisy in the fact that a religious conservative who promotes the idea that marriage should be between one man and one woman would cheat on his wife.

Sanford has been widely considered a possible Republican presidential nominee for 2012, but the likelihood of that happening now has at the very least been dramatically diminished. 

The full press conference is online here.

(Image is a still from today's press conference.)