Before the results of the Chesapeake primary start coming in tonight, we wanted to take a quick look back at Maine, where Sunday's caucus results were overshadowed by the news that Senator Hillary Clinton was shuffling her top staff.

The question is, why did Mrs. Clinton lose?

Maine, after all, was supposed to be one possible ray of sunshine for Mrs. Clinton in an otherwise gloomy February, which began with a split and inconclusive Super Tuesday outcome and saw a wave of successes by Senator Barack Obama.

The state's demographics fit the profile of those who have voted for her elsewhere: many voters are older, blue-collar and largely high-school educated; they make less than $50,000 and are concerned about health care and the economy. As of the spring, when the last statewide poll was done, Mrs. Clinton was 17 percentage points ahead of Mr. Obama.

But in Sunday's caucuses, Mr. Obama overpowered her by almost 20 percentage points.

The outcome could be instructive to the Clinton camp as it looks beyond Virginia, Maryland and the District of Columbia today and sets its sights on Ohio and Texas, which vote March 4. Mrs. Clinton's own advisers have said those contests are her firewall against an Obama nomination.

There were no exit polls in Maine, so we can't be sure of who voted for whom and why, but the geographical breakdowns give some indication.

Mrs. Clinton won in the mill towns and rural areas, according to results posted on the state Democratic party's Web site.

But Mr. Obama won the population centers, where younger, more affluent, college-educated people tend to live, including Portland in the south and Bangor in the north as well as Augusta and Waterville.

The only sizeable area that Mrs. Clinton won was Lewiston, a former mill town that has lost a lot of manufacturing jobs and which she visited on Saturday, talking bread-and-butter issues. She also won narrowly in Biddeford. But Mr. Obama won much of the wealthier parts of coastal Maine, including Kennebunkport, home to the Bushes.

The most important factor that stood out to those in Maine analyzing the caucus results was Mr. Obama's superior organization. His people came in earlier, set up shop faster and penetrated more deeply into local communities, they said, while the Clinton camp did not really materialize until after Super Tuesday, when the results failed to clarify the race.

Mrs. Clinton then suddenly focused on Maine because of its potentially favorable demographics. Both camps, though, were by then in a mad scramble for any and all delegates, including the 24 in Maine, and the Clinton camp had just four or five days to organize.

Not only Mrs. Clinton, but her husband and her daughter, visited the state. Mrs. Clinton also had the support of the governor, John Baldacci, but his influence in the state was questionable and he had no machine to speak of to get out the vote on her behalf.

Yet, while Mrs. Clinton held two well-attended events on Saturday, Mr. Obama captured the attention, drawing 7,000 people into the Bangor Auditorium and leaving 3,000 more outside.

A day later, Mr. Obama won 59 percent of the vote and picked up 15 of Maine's delegates, while Mrs. Clinton won 40 percent and 9 delegates.

"A lot of the credit for what happened here goes to the Obama campaign, a grass roots campaign, that was very well organized, with precinct captains and precinct leaders getting people out," said Arden Manning, executive director of the state Democratic party.

"Obama made a gamble that Maine would count," he said.

Amy Fried, a political scientist at the University of Maine in Orono, agreed that Obama organizers were more visible and active and also said that his campaign "did an amazing job with the Internet." She said she signed up on both the Clinton and Obama Web sites to compare them. "I got very little on the Clinton side," she said. "But I got a lot from Obama, urging me to come in and work and telling me about events, just giving me lots more."

Mrs. Clinton has blamed the caucus process itself for her losses in state after state with caucuses, saying she does better in states with primaries because they afford a broader cross-section of people a greater opportunity to vote; caucuses, on the other hand, limit the time that people can attend.

However, as Ms. Fried pointed out, caucus-goers in Maine, unlike those in most states, were allowed to vote by absentee ballot, and they cast more than 4,000 such ballots by the deadline last Wednesday.

Moreover, the caucus was held on Sunday, when fewer people would be trapped at work. And as it happened, turnout in Maine on Sunday set a record, with more than 45,000 people participating in the Democratic caucus; the previous record was 30,000, set in 1980.

"To blame it on the caucus is silly because turnout was so high," Ms. Fried said.

And then there was the intangible quality of momentum. Maine voted the day after Mr. Obama swept three other states. "When someone wins something, people pay more attention and the coverage is positive," Ms. Fried said.

Like the tides along the craggy coast, that validation seemed to pull caucus-goers toward Mr. Obama.