But can a marriage survive such a devastating scandal, even if it's not being played out on a national stage?
Yes, according to relationship experts, but only after some serious work and the admission that "falling back in love" may not be possible, or even necessary.
"I see this all the time," marriage therapist Terry Real told "Good Morning America" today. "The big secret ... 'Oh, my God, I'm not in love with my wife.' Not being in love with your spouse is part of marriage. It doesn't mean you're in a bad marriage. ... It's perfectly normal to not be in love."
Marriage and family therapist Bethany Marshall said the first thing the Sanfords would need to work on is the governor's "appalling and remarkable lack of empathy" for his wife.
"How is [Jenny Sanford] supposed to respond to that?" Marshall said.
Real said, "This guy needs remedial empathy. What impact does this have on the person sitting next to you?"
Marshall said she would ask Stanford if he wanted to work on the marriage, and to explain the affair.
"They're going to have to establish trust without looking backwards, which is a very difficult thing to do," she said.
When Jenny Sanford discovered the affair, the two went into counseling.
But Sanford flew to Buenos Aires last month to see his mistress without telling his family, friends, security detail or staff, instead suggesting he planned to go hiking on the Appalachian Trail.
Jenny Sanford said she was crushed when she found out about her husband's secret trip.
"He was told in no uncertain terms not to see her," she told The Associated Press Saturday. "I was hoping he was on the Appalachian Trail. But I was not worried about his safety. I was hoping he was doing some real soul-searching somewhere and devastated to find out it was Argentina. It's tragic."
Despite the extreme publicity surrounding her husband's well documented affair, Jenny Sanford said she is not giving up.
"I am going to do [my] best to work on my marriage," she said. "I believe in marriage. That's the most important thing."
Following his latest admission, Sanford's office would not comment beyond saying it will "let the AP report stand."
South Carolina Attorney General Henry McMaster issued a statement Tuesday saying he has requested the State Law Enforcement Division to review all of Sanford's travel records to see if any laws have been broken or if any state funds have been misused.
The governor released a statement Tuesday afternoon saying he welcomes the investigation, which will clear speculation about whether he used state money, and added that he plans to cooperate fully.
The governor first met the now 41-year-old Argentinean woman -- described as "refined and professional" by her friends in Buenos Aires -- for the first time in 2001 at an open-air dance spot in Uruguay, the governor told the AP.
Sanford, who was serving his final term in Congress at the time, said the two began corresponding by e-mail after meeting on the dance floor.
"There was some kind of connection from the very beginning," he told The Associated Press, adding that he advised her that night on her failing marriage.
He then met her for a coffee date in New York in 2004 during the Republican National Convention. Sanford told the AP that neither of the first two meetings was romantic.
In a tearful news conference June 24, 2009, Sanford said his eight-year-long friendship with Chapur became romantic only in the past year. In Tuesday's AP interview, he revealed the relationship turned physical during a 2008 state economic development trip to South America, a trip for which he is reimbursing state money used on his tickets and other expenses.
"Now,I am frightened," he told the AP, describing his state of mind after the first physical encounter. "It was before safe. But now it's not safe. We gotta put the genie back in the bottle."
In impassioned e-mails -- obtained by The State, South Carolina's largest daily newspaper -- Sanford agonized over the two's "hopelessly impossible situation of love," as Chapur wrote, "You are my love. ... Sometimes you don't choose things, they just happen. ... I can't redirect my feelings, and I am very happy with mine toward you."
He continued to insist he did not use money from state coffers to finance his romantic trysts. He told the AP he flew coach for his two meetings with Chapur in New York last year, and paid for hotels in cash. Last week, he said he would reimburse the state for last year's commerce trip, but insisted he didn't do anything illegal.
On Monday, Sanford made his second appearance after the announcement at a state budget board meeting. He apologized again to his staff for "letting you down" and said he was sorry about the affair. He also reaffirmed his decision to stay in office.
Chapur publicly acknowledged their relationship Sunday in a statement read on Argentine TV.
Chapur remains under the radar because of intense media scrutiny surrounding her. But in a brief statement conveyed through a television report on Buenos Aires' C5N channel, she said she indeed was involved with Sanford and that the published e-mail correspondence between the two was obtained from her account by a "hacker."
The former journalist did not directly acknowledge the affair or mention the embattled governor's name, saying she won't speak about her private life, which has already been made too public and painful. But her statement offered extensive details about how "the author of this evil action" broke into her e-mail account. She denied that the hacker was a friend of hers.
Chapur's friends and colleagues told ABC News she is a sophisticated and intelligent woman, and that the relationship between the two was simply a matter of love.
ABC News' Lisa Fletcher, John Hendren and The Associated Press contributed to this report.