They've been running for over a year, spending more time and more money than any Presidential candidates in history, each surviving grueling primary bouts with able opponents whom conventional wisdom thought had a better shot at earning a chair in the Oval office.

Neither candidate is running as a party insider, and neither has been able to close the sale with the voters. If you don't already think you know all you need to know about John McCain and Barack Obama, then you've probably been in a coma for the last two years or sharing a cave with Osama bin Laden.

For most, it's been impossible to tune out the race that began before the surge in Iraq, when gas prices were around $3.00 a gallon, unemployment was steady at 4.6 percent, consumer confidence was the highest since 2002, Wall Street was the wonder of the world, Mike Huckabee was a serious contender, Republican frontrunner Mitt Romney was $42 million richer, John Edwards' pricey haircuts and sexual appetites were a secret, and the Democrats seemed likely to anoint Hillary Clinton after a perfunctory round of primary contests.

But as voters braved the cold Iowa winter early this year to weigh in at the country's first primary/caucus, it became clear that this election season's outcome would defy the pundits' prognostications. Barack Obama seemed to come out of nowhere, and even though John McCain didn't seriously compete in corn country, he believed that Mike Huckabee's victory demonstrated that the country was hungry for "change." He headed for New Hampshire, where he vowed to make believers out of those who'd given up on his come-from-behind fight.

Slowly, primary after primary, caucus after caucus, debate after debate, the two front-runners emerged. The voters were, in fact, looking for "change," as McCain had predicted and Obama embraced. While these two candidates had gotten more television exposure than Paris Hilton and Britney Spears combined, it still wasn't clear how they'd become poised to assume the most powerful job in the world.

Frontline, PBS' long-running investigative news series, returns this season with a two- hour special that attempts to peel back the mythic curtain surrounding Obama and McCain's historic rise. The Choice 2008 tells the two candidates' stories in parallel as it compares and contrasts the journeys that brought them within grasp of victory.

Producer/Director Michael Kirk started this epic undertaking around Thanksgiving 2007, long before the two parties decided on their stalking horses. This gave Kirk and his team some time to research the stories. "While waiting for something to happen to resolve Clinton versus Obama, we made a two-hour program called Bush's War, which aired in February," says Kirk. But the two camps still didn't have a clear nominee, and no one would talk to them until there was a decision.

As Kirk explains, "The Obama people were saying, ‘Sure, we'd love to cooperate with you, but we can't authorize anybody to talk to you in any way until there is resolution, because it would be untoward if we were to act like we were winners.' And the Clinton people were saying, ‘If they're not talking to you, we're not really going to talk to you.'" So Kirk and his team, including producer/reporter Jim Gilmore and co-producer/writer Paul Stekler, had to start working around the edges.

These edges grew and grew and by March, McCain's camp had come on board, and eventually the Choice team broke through with Obama's people. The result was an enormous amount of material. "We interviewed 60 people for the film, shooting two and two and a half hours per person," Kirk explains. "So we had 250 interview tapes lying around--maybe more, in some cases--and we have all the transcripts and all that stuff and you get down to about 12 to 14 characters. We shot a lot of people to get an understanding of these guys."

Kirk and his colleagues relied on insiders to tell the story. For McCain, it was fellow former POW Orson Swindle, who accompanies McCain at all times. And in Obama's camp, it was Harvard Law School classmate Cassandra Butz. "Both can kind of talk the philosophy of the candidate, if nothing else," Kirk notes.

While the insiders are close to the candidates, neither one is the candidate, and Kirk chose not to ask either McCain or Obama to sit down for a one-on-one interview. "Every time you do this, in my experience in biography, what actually happens is the people who are the least interesting or useful about their own biographies are the people that they are about," Kirk maintains. "They spin it; they protect it. It is the rare person who can sit there and talk to you candidly and not defensively about things that they did. Or not have kind of a rote response. Oftentimes you're just going to get a little better feel for the truth of an experience if you have others talking, even if they are not talking negatively about them. But you are just going to be able to organize better."

Barack Obama, from FRONTLINE: The Choice 2008 (Exec. Prod.: David Fanning; Prod./Dir.: Michael Kirk; Prod.: Jim Gilmore; Co-Prod./Wtr.: Paul Stekler; Prod.: WGBH Boston), which airs October 14 on PBS. Photo: Scout Tufankian/Polaris.

Instead, we rely on the observers to interpret the decisive moments that Kirk chooses to create the context for understanding the candidates' characters. The defining event for Obama's future in The Choice is his speech at the 2004 Democratic National Convention, where he positions his personal history as the quintessential American story. Kirk cuts away to show us Jesse Jackson's reactions, and we can only imagine that he must have been wondering what this eloquent, uplifting speech delivered by this vibrant, fresh face meant to the Black struggle. We see Chelsea Clinton, standing by Jackson's side, smiling and vigorously applauding. She's clearly captivated, like many of her generation, who've become Obama followers.

Her mother, Hillary, also rises to her feet and is visibly moved. Kirk muses, "We can only speculate that she's thinking, ‘Is this my vice president? Is this what Bill and I have worked for all these years?'"

For Obama, who's delivering a speech he's given many times before, it's a triumphant time at the podium that is likely to be regarded as one of the most transformative moments in American politics.

"You know what he is saying," Kirk posits. "Not only is he trying to integrate as he's spent his lifetime trying to integrate himself into a place into society as a black kid from a white family. It's that guy who is saying to America, ‘My effort at integration is an allegory.' And he happens to be saying this at exactly the time a lot of people in the Democratic Party are hungry for a transcender, not a divider."

This break with the past almost comes undone when his divisive pastor, Jeremiah Wright, surfaces. Says Kirk, "Wright is the ultimate test of his efforts at integrating himself, then transcending the politics of Jesse Jackson and other politicians and other black politicians, and to say ‘I'm just a politician who happens to be black.'"

How Obama handled the Wright crisis and the other major turning points that make up his metamorphosis into presidential contender reveals a candidate that's more than someone who has "captured lightning in a bottle," says Kirk. "I was surprised about the steel inside the guy. The toughness, the calculation."

This is revealed step by step, in one scene after another. Kirk takes us from Obama's Illinois State Senate race, where he stands up to a former candidate who wants him to step aside, to his Congressional campaign challenge against Bobby Rush, a revered ex-Black Panther and hero of the Chicago black political machine, to his winning a US Senate race and then crafting a two-year plan to become a US Presidential candidate shortly after arriving in the Capitol.

John McCain, from FRONTLINE: The Choice 2008 (Exec. Prod.: David Fanning; Prod./Dir.: Michael Kirk; Prod.: Jim Gilmore; Co-Prod./Wtr.: Paul Stekler; Prod.: WGBH Boston), which airs October 14 on PBS. Photo: Jason Reed/Corbis.

John McCain's capacity for survival becomes clear when we see how he reinvents himself after nearly losing his political career during the savings and loan crisis. Tagged as one of the "Keating Five," he becomes the most open politician in Congress and reporters embrace him. Says Kirk about the media and McCain back then, "You can say, ‘Geez, I like a tough guy. I like a John Wayne kind of character. I think we need one in the world.'"

The media's response to his open-door policy turned him into such a powerful brand that he decided to launch a Presidential bid with a bus tour dubbed the Straight Talk Express.

"No American candidate for any major office that I've ever seen has ever been so accessible to the press as John McCain was in the back of that bus in 2000," Kirk reflects. "I mean, even in early 2007, everybody could get on, ride around with and get their pictures taken with him, and no Presidential candidate has ever granted that kind of ongoing and regular access to the press. And people are only half joking when they say that McCain's base in the 2000 election was the press corps."

McCain realized he needed more than the slavish devotion of the press to get elected; he needed the Republican base. Kirk and his team trace McCain's clear-eyed hunt for the right wing of the party. "He's also a kind of pragmatist who works on another level, a level that might make you somewhat uncomfortable--what he had to do once he decided to run, what he had to do to capture Karl Rove and George Bush's base," Kirk explains. "And to see him do that and to do that to the extent at which a very experienced politician will maneuver himself and his positions to get support in such an obvious way was a very interesting exercise."

This marked a turning point for his cozy relationship with reporters. "I think it started to become more uncomfortable for reporters to give him a free pass on that stuff once they saw where he was headed," says Kirk. "In a way, he lost the press, and they lost him at the same time."

One of the most surprising characters in The Choice 2008 is former Senate Majority Leader Tom Daschle, who plays a role in each of the candidate's senate careers. He counsels freshman Senator Obama that if he's going to do it, he needs to map out a two-year plan to run before he's burdened with the baggage of countless votes he'll have to explain. Daschle, along with Senator Kennedy, also tries to woe McCain to switch parties. We're left to wonder if a wavering McCain decides not to make the leap because he can't be guaranteed that the Party will support his Presidential bid.

The Choice 2008 does a good job focusing on the process and the plot, but doesn't deliver on the details or the substance of the two candidate's actions. While we do find out that Obama's tenure as a US Senator was spent planning for a run at the Presidency, the program doesn't give us much of an idea about what he did as a community organizer, what articles he pushed as editor of the Harvard Law Review, why he sided with the Federalists on the Review or what he accomplished or stood for as a state senator.

Nor do we learn about McCain's legislative record, his years as a womanizer, Daschle's trips to McCain's ranch or the impact of the policies either is likely to pursue if elected. This may be more than any one program-even a two-hour special-can accomplish, but I wanted to know more about the substance of their political agendas and, in general, the issues and policies that are dominating this campaign.

Kirk says that's not the film he set out to make. "Most of the films I make are kind of character-driven narratives. I know everyone always says that, but I really believe in that, and that method has its limitations, which I'll freely admit. One of them, it's really hard to stop in the midst of telling a story about a character and say, Let's do a little investigative section right there and really smack him for having done this or not having done that."

Kirk agrees that providing this level of detail and context is one of the ways the Internet can work in concert with a broadcast--which is what PBS is doing this election season as it rolls out its PBS Vote 2008 election lineup that will enhance its over-the-air content from The NewsHour, Washington Week, National Journal, NOW on PBS, Bill Moyers Journal, Tavis Smiley and Frontline with unique content.

Kirk couldn't predict who was going to win or if there was going to be a much talked about "October surprise." He'd only say, "I think it's either going to be a slaughter or it's going to be really, really close. I don't think anybody knows what's going to happen when the curtain gets pulled and people go into that room."

If you're having a hard time making your choice, tune in tonight and watch The Choice 2008. Encore broadcasts are scheduled for Sunday, October 26, and Monday, November 3. In addition, viewers will also be able to watch the program in its entirety on YouTube (youtube.com/pbs) and download it free from iTunes beginning October 15 through the month of November. The Choice 2008 will also stream in the high-quality News & Public Affairs Player at pbs.org/frontline.

Michael Rose is a writer/producer/director.