In the midst of his presidential bid, Barack Obama is one of the most intensely scrutinized public figures in the U.S. But four years ago, if you asked him to identify the media horde dogging his steps, he’d have replied with a singular name: Chicago Tribune reporter and Forest Park transplant David Mendell.

That ongoing one-on-one contact, as Obama campaigned for his current spot as Illinois’ junior U.S. senator, set the stage for Mendell’s biography, “Obama: From Promise to Power.”

The book, 41-year-old Mendell’s first, was written largely in the basement of his home after tucking into bed his now 6-year-old son, Nathan. Published last August, the 416-page effort offers a wide-ranging look at Obama and the influences and decisions that shaped his life. Drawing on exhaustive reporting, Mendell employs a first-person perspective in chronicling Obama’s political ascent.

The biography, which promises to become a foundational work for future Obama historians, also represents a long journey for Mendell that began with him crouching at the side of a vending machine.

It was there, in the Tribune’s downtown Chicago newsroom, that Mendell took refuge one day in September 2003 to duck an approaching editor. Shortly after covering Illinois Gov. Rod Blagojevich’s successful campaign, Mendell had heard the editor hint that he was looking to assign him to cover the wide-open race for outgoing Illinois Sen. Peter Fitzgerald’s seat.

Mendell said he considered it a “dog of an assignment” but knew that within a few days he would have little choice but to take it on.

As he recounts in the book, Mendell first met Obama by arranging to sit in on a lecture the constitutional law professor was giving at the University of Chicago. Over the next four months, Mendell said, “I had the luxury of lots and lots of time with Obama, just unfettered access.”

“People [now] are asking questions trying to learn who he is, and I had a pretty good sense of who he was just because I had been around him so much,” Mendell said. “At the beginning it was me chasing him around in his Jeep.”

As other candidates’ political fortunes sank amid lurid divorce revelations – first Democratic front-runner Blair Hull in the primary race, and later Republican Jack Ryan in the general election campaign – Obama broke from the pack.

He then burst onto the national scene with his speech at the 2004 Democratic National Convention in Boston.

“After the Boston speech, I took much better notes. I could see that there was something going on here,” Mendell said. “That’s when it probably first entered my mind – I didn’t know if it would be a book, but certainly that I should keep track of this very closely.”

Mendell received four or five rejections from publishers. He began entertaining thoughts of ditching the idea, though his resolve to pursue a book prevailed.

“At its essence, I was a reporter following this magnificent story and it was almost impossible to let it go, once I saw what was happening and that this guy was blowing up into this superstar,” Mendell said. “I felt like it was a tremendous story to keep following.”

In early 2005, he contacted literary agent Jim Hornfischer, a Texan who has helped shepherd numerous biographies into print over the past 20 years.

Hornfischer encouraged Mendell to expand the scope of the project beyond Obama’s campaign for the Senate. He also helped Mendell develop the 35-page proposal that in April 2005 won a contract from Amistad, a division of HarperCollins.

A key element, said Mendell, was Hornfischer’s instructing him to highlight his longtime access to Obama high atop the proposal – a point that Mendell had previously noted almost in passing.

Hornfischer acknowledged the initial difficulty of marketing a book about Obama, given that he had already written two best-selling autobiographies. Mendell’s skill as a “very practiced and mature story-teller” helped overcome that concern, said Hornfischer.

“He knows how to set the stage, how to build a scene and to use the scene to make points,” Hornfischer said.

Mendell traveled extensively to track Obama’s life story – to Boston, New York, Washington, D.C., Philadelphia, Wisconsin, Hawaii, South Africa and Kenya. The six months after Obama’s trip to Africa – the last part of 2006 and the first few months of 2007 – was the most frenzied writing time for Mendell.

Mendell took several unpaid leaves from the newspaper, and at this stage he took his final one, a three-month hiatus, from January to March 2007, to focus on finishing the book.

He had two overriding objectives for the work: “get it right” and “be a good read.” It wasn’t easy. He re-wrote the first chapter six times. He agonized over what details to keep in, and which ones to leave out.

“Everyone told me how hard it would be and I believed them. It’s a very lonely process,” he said. “You spend a lot of time on your own with this blank screen.”

When Mendell began writing the book, Obama was hardly a shoo-in as a viable presidential contender. But then came the unfolding of The Plan, as Mendell refers to Obama’s advisers’ blueprint to heighten Obama’s political profile over his first few years in the Senate. As The Plan took shape, the specter of a run for the White House came more prominently into view.

Correspondingly, Mendell developed a rising sense that his book could potentially have an impact on the country’s future. When he confided to his father that he was feeling more pressure than he bargained for in his first book, dad splashed some cold water on him: “I think you have delusions of grandeur,” Earl Mendell told him.

Chicago Tribune staff writer Bob Secter was the newspaper’s political editor when Mendell covered Obama’s campaign for the U.S. Senate.

“The American public is divided on Obama,” Secter, a River Forest resident, said. “The people either adore him and want to excuse any flaw … or you get the side [saying] he can’t do anything right.

“I think Dave carefully navigates a story about a guy who became a rock star,” Secter said. “He gives us both the inside story about how that happened and how that affected [Obama] and how’s he responded to it.”

Journalism roots

Mendell grew up in Delhi Township, a suburb of Cincinnati. His mother died when he was 7 and Mendell, an only child, drew especially close to his father, who was about to turn 50 when Mendell was born.

Earl Mendell was a “news junkie” and that rubbed off on Mendell, who went across the Ohio-Kentucky border to pursue a journalism degree at Northern Kentucky University.

His first professional bylines came covering high school sports for the Cincinnati Post on weekends. After graduating in 1990, Mendell landed in Lorain, Ohio, a Lake Erie town about 30 miles west of Cleveland. Within two months at The Lorain Journal (now The Morning Journal), he was dispatched to cover city hall.

John Cole, who was editor during Mendell’s time there and remains in that post, said Mendell quickly distinguished himself as an aggressive reporter of integrity amid “rough-and-tumble politics.”

“They’re used to having reporters for breakfast down there … he was unfazed by it. He saw it as an opportunity to do great work,” Cole said. “I never saw him back down an inch from anybody anytime. He does it despite being the most polite, soft-spoken gentleman, but he’s pure grit. I just think the world of him.”

Mendell broke investigative stories of public corruption that resulted in the mayor and city engineer getting indicted. Along the way, he received a veiled threat of physical harm from an influential community leader.

He chuckled at the memory of stacking empty beer cans against the back door of his house, so he could be alerted in case an intruder was coming to attack him.

“It gave me a lot of confidence in my abilities,” Mendell said of that time in his career. “Also, it toughened me up a lot. When you get your life threatened, suddenly asking a politician a tough question doesn’t seem all that difficult any more.”

Mendell was in Lorain for four years, then joined The Dayton Daily News in 1994 before moving on to the Tribune in 1998.

Mendell faces the media

“Do you like Obama?”

Mendell doesn’t flinch when asked the question. Instead, he takes control of the dialogue by beginning his answer with a question: “Does a scientist like his lab rat?”

“He was a subject for me,” Mendell said. “So you start looking at somebody not as, ‘Do I like him or dislike him?’ You just start studying this person. I wrote in the book that he is a likeable person. Most politicians are likeable or they have to get people to like ’em. So I would say he is a likeable fellow.”

Mendell now finds himself in the position of being a source for a wide range of media with a limitless hunger for all things Obama. A French television crew, a British TV crew and a crew working on a documentary for a Hollywood production company have all interviewed him.

He has done dozens of other media interviews since writing the book, including numerous radio programs and television appearances such as “Meet the Press,” “Good Morning America,” “Hardball with Chris Matthews,” and the “NBC Nightly News.”

On “Meet the Press,” host Tim Russert asked Mendell the “most important thing” the public should know about Obama.

“For a politician who’s gotten to the level that he is,” Mendell responded, “I found him in personal situations to be extremely honest with me – straightforward, candid.”

Mendell also touched on what he calls one of Obama’s weaknesses.

“He does not have the capacity to really take himself unseriously,” Mendell said. “It’s just not him.”

Obama’s staff did not respond to requests for comment on the book.

“I hope I presented a three-dimensional character,” Mendell said. “I got kicked around by both the pro-Obama people and the anti-Obama crowd, so I figure I must have done something right.