COUNCIL BLUFFS, Iowa – Pat Snook knows what he wants even if he still hasn't settled on whom he will support when Iowa Democrats hold their presidential caucuses in just over four weeks.

“Right there,” the 45-year-old systems analyst said as he jabbed his finger at a campaign brochure with the word “CHANGE” in bold letters. “I want it.”

That was good news for the candidate who had put out the brochure, Illinois Sen. Barack Obama, who has based his campaign on a promise of change. It was bad news for Obama's main competitor, New York Sen. Hillary Rodham Clinton.

“No way! No,” Snook all but shouted when asked if he would support Clinton. “We've been governed by Clintons and Bushes for 20 years, and it's time for them to go. We don't need another one. That wouldn't be change.”

Snook had come to a middle school cafeteria early on a cold and dreary morning to listen to Obama make his pitch, hoping it would help him choose between Obama and former North Carolina Sen. John Edwards.

For Obama, the speech was another sign that his campaign is hitting its stride at just the right moment, as Iowa gears up to take the first official step in the 2008 presidential election with the caucuses on Jan. 3.

At Council Bluffs, Obama attracted about 400 Iowans. Later in the day, he drew similarly large and enthusiastic audiences in Dunlap, Harlan and Audubon. Except for Clinton, no other candidate in either party is drawing so many people.

Gone is the somewhat tentative candidate who almost seemed aloof and wary of voters earlier in the campaign. Instead, here was a folksy, relaxed Obama who used humor to great effect and fed off the energy of the crowds.

“He's doing retail politics better than he was before, and he's being less of a law professor and a little bit more of the ambitious politician,” said Peverill Squire, a longtime expert on the caucuses at the University of Iowa.

Almost everything has gone right for Obama in the past three weeks in Iowa. He gave a rousing and well-received speech at the state party's big Jefferson-Jackson Day dinner on Nov. 10 and got a momentum boost from the release of a poll Nov. 19 showing him narrowly ahead of Clinton here – even though statistically, the poll showed them virtually tied. The next day, he drummed up more excitement by announcing that Oprah Winfrey is headed toward Iowa to stump for him.

“We built the best organization, and now the candidate is getting hot at the right time,” said Gordon Fischer, the Des Moines lawyer who headed the state party four years ago and now is a senior adviser to the Obama campaign. “With Oprah coming, there is a real sense of movement and momentum here.”

Cary Covington, who teaches a course on the Iowa caucuses at the University of Iowa, said the Winfrey announcement “has created quite a buzz” in the state and gives Obama a chance to take some momentum into the final weeks of the Iowa campaign.

“He kind of arrived all at once and staked himself to 20 percent of the electorate. But then he just plateaued and didn't go anywhere,” Covington said. “Now it looks like he is breaking out of his plateau. That is the thing that his people have to be most excited about – he's getting out of this static situation of not being able to grow his base of support.”

The Nov. 19 ABC/Washington Post poll had Obama at 30 percent, Clinton at 26 percent and former North Carolina Sen. John Edwards at 22 percent. Polls before and since show Clinton with at least a slim lead or tied with Obama.

When addressing audiences, Obama is both easy and energized as he hammers home the message of change.

“I hear candidates saying, 'Elect me because I've been in Washington a long time and I know how to play the game better,' ” Obama said in a visit to a cattle auction house in Dunlap. “We don't need somebody who knows how to play the game better. We need somebody who can put an end to the game playing.”

And he mocked those who say he is too naive or too inexperienced in the ways of Washington. He said they call him “a hope-monger, a hope-peddler.” To applause, he added: “I oftentimes tell people in Washington (that) part of the reason you don't have a lot of hope is because you've been in Washington too long. . . . I keep thinking they want me to stew and season in Washington longer. They want to boil all the hope out of me.”

As always, Obama's target in this vein is Clinton, even if he doesn't mention her by name. He invokes the change theme frequently on Iraq. He opposed the war from the beginning; Clinton did not.

Although themes on change and the war resonate with many Democrats, some remain troubled by Obama's lack of experience at age 46.

“For me, it is Hillary's experience versus Obama's change,” said Russ Lombardo, 55, a drug counselor in Council Bluffs. “When I think of Hillary, I think about that 16 to 18 years of experience that she has in that arena. When I think of Obama, I like what he has to say about being more engaged in the world community and less trying to be the world's policeman.”

Everette Carroll, 66, a retired schoolteacher in Harlan, also is torn.

“Obama is putting out a message that people want to hear – change, but not terribly drastic change,” he said. But Carroll is bothered by “his lack of political experience, especially overseas at a time of war.”

But Fischer, the campaign adviser, said more Iowans are coming over to Obama.

“The trends are clear – Obama is going up, Hillary is staying the same or dropping a little, and Edwards is definitely dropping,” Fischer said.

The caucus system presents a great unknown. Analysts say Clinton and Obama are attracting a number of potential first-time caucusgoers, who historically have a spotty record of showing up when it counts.

At the least, Obama is going to make Jan. 3 an interesting night, said Squire, the caucus expert.

“He has weathered the Hillary storm and, at least in Iowa, is still slugging it out toe-to-toe with her,” Squire said.