Laura Bush: An Intimate Portrait

(CBS)  A quiet and forceful presence in the White House, Laura Bush has made her mark on history. And while her approval rating hovers around 80 percent, she has managed to keep much of her life and past off limits to the public.

Ronald Kessler has written a new biography, "An Intimate Portrait of the First Lady: Laura Bush," the first to be written with the cooperation of the White House. And it reveals that the woman behind the president may have more influence than we thought, guiding the direction of many policies and weighing in on key appointments.

In fact, after what he's learned, Kessler believes George Bush would not be president if not for Laura Bush.

"First of all, she definitely guided him to give up drinking. I say guided because she was very subtle. She doesn't say I'm going to leave you," he told The Early Show co-anchor Hannah Storm. "After a while people who are with her realize that she's very firm. She's tough. And she has great judgment. And so they start listening. That's what happened with our president."

Part of what has shaped the first lady comes from a tragedy in her past. When she was 17 years old, she ran through a stop sign and killed a high school classmate. A passenger who was in the car that night spoke with Kessler and said it was a blow that changed her friend for good.

"She felt that she became certainly more serious, more introspective, more appreciative of life, of course, because this very close friend had been killed in this accident," Kessler told Storm. "So she overcame this tragedy, and she's always been rather tough, even though she seems so charming and classy, which she is."

Tough, yes, but always very positive, according to Kessler, who went back to a story from the last presidential race, in which Teresa Heinz Kerry made the comment that Laura Bush had never had a real job. That comment triggered a lot of anger, but Bush kept a level head.

"Laura said just what she said publicly, 'I understand these things get taken out of context,' and she knows. She's very savvy. She knew what was going on. She chooses to look at life in a very positive way," he said.

Even Laura Bush has her vices, such as a smoking habit she can't quite shake. Kessler says the first lady bums a cigarette once in a while: "She goes out on the balcony and smokes a little bit every now and then."

And he writes about her struggles with fertility, for which she eventually had to seek treatment. "She actually signed up for adoption three years after getting married, and finally did take medication, which resulted in the twins," he told Storm.

As for her habit of shrinking from the spotlight, Kessler describes it as nearly pathological.

"Believe it or not, she doesn't even watch herself on television. She tells her speech writer not to use the personal pronoun 'I' in her speeches," he said. "She's happy to talk about policy, after 9/11 she was very happy to reassure the nation, but it's … almost pathological that she doesn't really ever want a focus on herself."

Kessler's book is based on interviews with Bush's closest friends and confidantes from childhood to the present, as well as family members and administration heavyweights like Condoleezza Rice and Andrew Card.

To read an excerpt, click here.