CHAPEL HILL, N.C. - Last July, as Barack Obama's campaign began considering how to allocate resources among the two dozen states that would vote on Feb. 5, Jon Carson realized that some of the biggest gains could come from the smallest states.
Idaho, for instance, would have one caucus site in each of its 44 counties - which made a trip to a polling place so burdensome in 2004 that only a few thousand people bothered to vote. A campaign that was able to identify its supporters and move them across long, often mountainous, distances could overwhelm the caucuses and take a large share of the 18 available delegates.
"We felt like that would be a place where the extra organization would really pay off," said Carson, Obama's national voter-contact director.
Seven months later, it did, as Obama won the state by a margin rarely seen outside autocracies. Obama carried Idaho with 80 percent of the vote against Hillary Clinton; in Kansas, where caucuses were held in each of the 40 state Senate districts, Obama won 74 percent. Because the states allocated delegates on a proportional basis, Obama left Idaho with a net gain of 12 delegates and Kansas with 14. That same day, Clinton won New Jersey's primary by 10 points, but earned only 11 more delegates there than Obama.
Obama's commitment to the votes of small states the week of Feb. 5 - the culmination of months of largely unrivaled attention to those states - has come to define the race. In the week's 10 caucuses alone, Obama tallied more than twice as many delegates as Clinton, a net gain of 113 delegates that Clinton is still trying, vainly, to overcome.
"That's really the heart of his advantage," said Tad Devine, a delegate strategist for Michael S. Dukakis in 1988. "In a system of proportional representation, if you get ahead in elected delegates, it's almost impossible for the trailing candidate to catch up."
As Obama confronts his first prolonged downturn of the campaign - with a sequence of major primary losses to Clinton, a shrinking popular-vote margin, and new skepticism about his general-election viability - he continues to guard the slender but apparently insurmountable lead in pledged delegates accrued with wins in early February. Now up to 154 delegates, according to Associated Press estimates, Obama's advantage continues to set the terms of negotiation for the support of superdelegates who will be essential to either candidate's nomination.
"If the votes of the superdelegates overturn what's happened in the elections, it would be harmful to the Democratic Party," House speaker Nancy Pelosi told ABC in March.
What has now become a structural advantage for Obama had its roots as a tactical gambit conceived over a series of meetings last June at his Chicago headquarters. At the time, the Democratic primary calendar was just beginning to take form, and a number of states moved up their primaries and caucuses to Feb. 5, the earliest date permitted by new party rules. That day, nearly half the total number of elected convention delegates would be up for grabs, creating a broader - and potentially more expensive - playing field than many campaigns face in a general election.
Clinton's campaign approached the day as an insurmountable hurdle for Obama and former senator John Edwards, assuming that only a nationally established candidate could have the stature and resources to compete in a de-facto national primary.
"They thought they would win enough early support in the early states and on Super Tuesday to convince other candidates to drop out," said Barbara Norrander, a University of Arizona political scientist who specializes in presidential primaries.
Obama, however, had already begun looking past the early states whose votes were the primary focus of attention of the media and the campaigns. "We were relatively sure that the first four contests - Iowa, New Hampshire, South Carolina, and Nevada - would not end the race, and that it would go on to Feb. 5 and probably beyond that," said Steve Hildebrand, a deputy campaign manager.
If Obama passed that threshold, he would probably enter a long race that would be determined not by attrition but by arithmetic. "Right from the start, they said this is a race for delegates," said Gordon Fischer, a former Iowa party chairman who endorsed Obama. "Even before I came onboard, I heard that."
Obama's campaign divided the Feb. 5 states into three categories: primaries like Illinois and Georgia they expected to win; those like New York and New Jersey where Clinton would be strong but Obama could work to minimize her delegate advantage; and the caucuses, the most demanding to organize but where Obama's appeal to party activists offered him a potential base of support.
"Our hope at that point was that we would have enough money to fully compete in all those states," said Hildebrand. "We just didn't know how our fund-raising would go. It was a little bit of a leap of faith."
In early June, the campaign used a "Walk for Change," a nationwide day of canvassing, to test its strength among activists and volunteers - assigning extra canvassers to Feb. 5 states to gauge Obama's potential in each.
"What we knew was that in caucus states you can't go in 30 and 60 days out [from the caucus day] and expect to be able to compete," said Hildebrand. By September, Obama had begun opening offices and assigning staff to many of them.
"I was slightly surprised and intrigued by their willingness to do it," said Wayne Holland, the Democratic party chairman in Utah, a primary state where Obama eventually had three offices. "We've never had even one single presidential campaign set up shop for a long time in Utah."
By the end of 2007, both Clinton and Obama had raised nearly equal sums of money, around $100 million each. "What differentiated the two campaigns was the nature of the investments each of the campaigns made," said Alan Solomont, Obama's Northeast finance chairman.
After Obama won Iowa and Clinton won New Hampshire, Obama sent his well-regarded Iowa field director, Anne Filipic, to Utah, which he eventually won by a margin of 58 to 42 percent, earning five more delegates than Clinton. "Without the resources they put in to the field organization in January, it would not have been" such a decisive margin, said Holland, a superdelegate who later endorsed Obama.
Obama's commitment to small states came often at the expense of large ones, where candidates had traditionally sought strong performances to generate national momentum and demonstrate strength to party elites, fund-raisers, and the media.
"The Obama people could have spent more money in California on television and reduced the margin here a little more, but they didn't see the delegate gains they would get out of that," said William Carrick, a Los Angeles consultant not working for a candidate.
And Obama was already making a concerted effort to nudge the media to focus on the delegate race. When early news reports after Nevada's caucuses on Jan. 19 declared Clinton the winner based on the statewide popular vote, Obama's campaign hastily called reporters to claim victory after it became clear he would emerge with more delegates, 13 to 12.
"It was a very smart move to work so aggressively to get the media to recognize that," said Devine. "In retrospect, that one delegate was a big one."
Clinton and Obama split the Feb. 5 delegates almost evenly, and his campaign expected to end the primary season with 1,806 delegates to 1,789, according to an internal campaign projection obtained by Bloomberg News. The next morning, Obama announced that whoever won the most pledged delegates should be the presumed nominee.
"If this contest comes down to superdelegates, we are going to be able to say we have more pledged delegates, which means the Democratic voters have spoken," Obama said.
A week later, Clinton dismissed Obama's small-state victories as irrelevant to the general election. "Unless there's a tsunami change in America, [Democrats] are never going to carry Alaska, North Dakota, Idaho," she told the Politico, a Washington news organization, in mid-February.
She has continued making that argument to the party's superdelegates - that the states she has won prove her to be a stronger nominee even if they yielded fewer elected delegates - while Obama has maintained his numerical advantage and moved closer to the nomination.
"Obama did it the old-fashioned way," said Donna Brazile, a strategist and uncommitted superdelegate. "He went everywhere to pick up anything available."