Author: Barack and Michelle Almost Split

Michelle and Barack Obama's marriage was so shaky at one point that they almost separated, according to a new book that gives what it says is a behind-the-scenes look at the Obamas' life together.

In "Barack and Michelle: Portrait of An American Marriage," author Christopher Andersen also says the Obamas had lots of trouble conceiving when they wanted to start a family, Michelle gave a thumbs-down on Hillary Clinton as a possible running mate for Barack, and persuaded him to go with the campaign slogan "Yes we can!" which he considered corny.

Andersen writes that Barack's overriding political ambition caused a wedge between the two so serious that they almost split up. "I think she could have walked at one point. She felt abandoned."

"The strains in their marriage, they've been very open about," Andersen told "Early Show" co-anchor Harry Smith. "During the period when he was in the senate, the State Senate, in Illinois, he said it was a dark time in their marriage. It was angry all the time."

But a terrible scare brought them back together when Sasha was diagnosed with spinal meningitis in 2001.

Andersen also writes that the Obamas had a rough road having children. "For five years," he summed up for Smith, "they tried to have children, and they were very concerned about their ability to have them before Malia came along. And, in fact, one of their best friends has gone on record as saying when she became pregnant, she was afraid to tell Michelle, because Michelle had been trying so hard and she didn't want to break her heart. They discussed adoption with some of their closest friends and then, fortunately for them, Malia came along in 1998."

Michelle "had very strong input" into Barack's decision to bypass Hillary Clinton as a running mate, Andersen told Smith. "Barack Obama has said repeatedly that, 'She is my chief counsel, my chief adviser, I would never make a decision without going to her and asking her opinion,' " Andersen remarked. "She, in fact, gave her opinion, and that was -- she asked him if he really wanted to have Bill and Hillary down the hall in the White House. 'Can you live with that?" "

And, Andersen says, Michelle pushed for "Yes we can!" "The campaign has verified that," he pointed out to Smith. "The fact of the matter is that, when David Axelrod, his campaign manager, floated this by, he didn't like it at all. He thought it was childish and corny and she said, 'No, trust me, I know it will work.' So she was the deciding factor there."

Andersen defended the research he did for the book, noting he'd interviewed roughly 200 people who've been closest to Michelle and Barack over the years.

To read an excerpt of "Barack and Michelle: Portrait of An American Marriage," click here.