WASHINGTON— Jenny Sanford was my role model, until I read her book. Well, not role model, exactly, but improbable heroine. When her cheating, blubbering, disappearing-with-his-soul-mate husband turned up on national television to confess that he had not been hiking the Appalachian Trail, Jenny Sanford was neither standing by his side nor crawling into a hole.

As I wrote then, the wife of South Carolina Gov. Mark Sanford offered “a new and improved version of the betrayed political spouse — neither enabler nor victim.” In contrast to her moonstruck husband, Sanford had her feet on the ground. “I believe enduring love is primarily a commitment and an act of will,” she said in her statement the day of her husband’s rambling news conference. She confronted his adultery with the toughness one might expect of a one-time Lazard Freres investment banker. “He was told in no uncertain terms not to see her,” she told The Associated Press.

Then I was asked to review Sanford’s new book, “Staying True.” The delicious part is that Mark Sanford is an even bigger heel than you thought — than I thought, and that’s saying something. This is a man who had the nerve to call his wife, post-news conference, and ask, “How’d I do?” Who, after another other woman surfaced, called his wife and asked “what I thought he should reveal in the interview.” If “Staying True” is Jenny Sanford’s payback time, it must be said: He gave her a lot to work with.

The disappointing part is that Jenny Sanford is, well, the very victim I had imagined her not to be. The book is replete with instances of Jenny-as-doormat, from the very start of their relationship and continuing, excruciatingly, months after her discovery of his affair.

After one of the all-too-rare pre-affair moments in which Jenny gets angry, Mark enlists leaders of a congressional Christian fellowship to talk her down. They told her she was right to be angry, Jenny recounts, but that “staying angry with Mark was not an option. If I wanted to heal the relationship, I had to open my heart and be kind, even if Mark was in the wrong. They would work on Mark. We even went so far as to talk about sex and (one of the leaders) told me not to withhold it as punishment as that would make everything worse.” Worse, I wonder, for whom?

The creepiest moment, though, and even Jenny seems to recognize this in retrospect, is when she lets her husband go to New York for two nights to see Maria Belen Chapur, his supposedly-ex-mistress — accompanied by a friend-cum-chaperone to keep him in line.

“Later in the year, when I confided in friends about what was happening and what Mark was asking to do, I better understood that allowing him to see Belen in New York — which is what I eventually agreed to let him do — was ludicrous,” Sanford writes. “Of course, it was ludicrous of him to continue to ask me to let him go, but he wore me down, asking again and again and insisting that the way for this to be over was to allow him the closure he needed.” Sorry, but the only closure that Mark Sanford needed at that point involved his zipper.

So the disturbing question about Jenny Sanford remains: Why would a woman so obviously smart, well-educated, successful and attractive allow herself to be treated so badly for so long? Sanford’s situation may be uniquely public, but she is certainly not alone in allowing herself to be undervalued — indeed, in undervaluing herself. I confess: I am better at diagnosing this tendency than I am at explaining it; I’ll leave discussions of women and self-esteem to the psychologists, pop and otherwise.

In the meantime, though, I’m bringing home my copy of “Staying True” for my teenage daughters. If they read it as a how-not-to dating manual, maybe Jenny Sanford will end up my heroine after all.