Jenny Sanford: Not Standing by Her Man

Unlike so many other political wives who have been faced with cheating husbands, Jenny Sanford is not standing by her man, and she's discussing it in her new book, "Staying True."

Her husband, Gov. Mark Sanford, mysteriously vanished for four days last summer. When he resurfaced, he confessed to a clandestine trip to Argentina to be with his mistress, and revealed it in a rambling press conference -- unattended by Jenny.

Mrs. Sanford tells Barbara Walters on Friday's "20/20" about how she discovered the affair and the humiliation and disbelief she experienced. She also discusses how she left her husband for the sake of her own and her children's well-being, saying, "Mark needs to resolve a lot of his unresolved issues on his own."

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Watch the whole interview tonight on ABC.