DES MOINES - Jeremy Davis was driving past lush Iowa pastures on his way home from work one recent afternoon when his cellphone rang.

He didn't recognize the number. But Davis, a farm-bred Republican newly elected to the Ames City Council, answered.

"Is Jeremy Davis available?" a voice asked. Then the caller added: It's Tim Pawlenty.

So began a crucial political courtship as the miles rolled by on I-35 -- one more sign of how the former Minnesota governor's presidential campaign is being built in this early caucus state, one operative at a time.

Davis, 33, is a rising star in Iowa Republican circles. That makes him a valuable foot soldier in the grass-roots network Pawlenty needs in his win-Iowa-or-bust quest for the White House.

No one wins the Iowa presidential caucuses without a thriving political ground game and the support of community leaders like Davis, who can persuade voters -- people who are their neighbors and friends -- to express their presidential preferences in public on caucus night.

Eventually Pawlenty's campaign across Iowa will be a traditional blitz of television commercials, yard signs and doorknocking. Right now, the name of the game is locking up local leaders.

"It's really about making the connection with the activists," said Eric Woolson, another key Pawlenty recruit who managed Mike Huckabee's winning 2008 caucus campaign in Iowa. "It's the epitome of retail politics, very much word-of-mouth and personal relationships.''

With his family ties to farming and a government relations firm in Des Moines, Woolson is no slouch in the business of political relationships. He worked for George W. Bush's campaign and served as a spokesman for Iowa Gov. Terry Branstad, who might someday make a highly sought endorsement.

What institutional knowledge Woolson doesn't keep in his head can likely be found in the piles of papers sprawled over the backseat of his high-mileage, 2003 Hyundai. "I think I have my taxes back there," he joked during a sprint to do a news interview about Pawlenty for WHO-TV 13, the local NBC affiliate.

Branstad is still neutral in the race, but Pawlenty has received a boost from a number of new allies, including Chuck Larson, a former chairman of the Iowa Republican Party; Nicole Schlinger, Mitt Romney's 2007 straw poll director, and Ed Failor, former president of the influential Iowans for Tax Relief.

"This is just a big job interview with a whole lot of Iowans," Failor said of Pawlenty's inroads in Iowa, a state Pawlenty has visited 14 times since the 2008 presidential election.

Empty spaces

Pawlenty's Iowa headquarters sit in a low-slung, suburban office park behind the Urbandale Dragon House Chinese restaurant, just outside of Des Moines. The office shows more ambition than real organizational presence. It currently houses vast swaths of empty blue carpet, long corridors of mostly bare walls and a staff of 10. Perhaps in a sign of changing fortunes, it turns out to be Romney's old office from 2008.

The day before the formal announcement of Pawlenty's candidacy in Des Moines, three campaign workers crowded around a cluster of desks facing each other in an cavernous room. Working the phones, they wore headsets connecting them to potential supporters, part of an effort that produced a turnout of more than 200 people, or "packages," as they're called in the business.

One prospect the campaign corralled was Sheryl Hickle, a 55-year-old animal clinic worker, member of the Indianola Heights Evangelical Free Church and registered Republican. Walking with a cane, she would need a ride, which she got the next day from a young man she knew only as "Andrew."

Arriving in an "I (heart) Jesus," T-shirt, Hickle represented the religious conservatives Pawlenty must win over from Huckabee and fellow Minnesota Republican Michele Bachmann, who followed Pawlenty to Iowa last week.

Hickle said she backed Huckabee in 2008. This time? "It's between Tim Pawlenty and Michele Bachmann," she said.

Even as Pawlenty meticulously works his plan in Iowa, he is dogged by doubts about whether he can fire up die-hard conservatives the way Bachmann can. One group of influential Iowa Republican donors, still dissatisfied with the GOP field, traveled to New Jersey over Memorial Day weekend to urge popular Gov. Chris Christie to get into the race.

On the ground in Iowa the past week, Pawlenty found that the rituals of retail politics aren't always seamless. At Casey's Bakery in Sioux Center on Tuesday, he took questions from a group of eight people who closed into a small semi-circle around him. A scheduled visit to the Blue Bunny Ice Cream shop in Le Mars was cancelled at the last minute because the business was moving. He also had to scrub a town hall meeting at Sioux City because of floodwaters. Rather than create a conflict for volunteer sandbag fillers, he went out to help fill sandbags himself.

His aides say their caucus strategy relies less on big media splashes aimed at undecided voters than on delivering the party faithful to churches, schools and homes where caucuses are held. "You don't get people to the caucuses with a lot of cash," said Pawlenty's new state campaign director, Erik Helland, the Republican majority whip in the Iowa House of Representatives. "It isn't rocket science. You just have to work hard."

'I said yes'

Supporters like Davis say Pawlenty has certainly given the impression of working hard and diligently, a prerequisite for the affections of caucus-goers who are accustomed to being heavily wooed by top national names.

With roots on a 700-acre family farm in Olin, where his parents still grow corn and soybeans, Davis is almost the political mirror image of Pawlenty: a conservative voice on a largely liberal city council in Ames, the home of Iowa State University.

"Communicating a conservative-leaning message in a liberal-leaning community tends to be kind of unique," Davis said of his connection to Pawlenty.

So when Pawlenty called to ask that Davis lead his campaign in Story County, he found a receptive ear. The position would give Davis, an up-and-comer in the party, a big role in the Republican straw poll on Aug. 13 in Ames, a critical test of candidate strength.

Driving home from his job at the Iowa College Student Aid Commission, Davis probed Pawlenty on the phone about his take on the national debt, Davis' central concern.

Davis liked what he heard. But Pawlenty wouldn't close the deal right away.

"When we wrapped it up, I basically said I wanted to seriously think about it overnight," Davis said. "And he reiterated the fact that they really wanted to move forward as quickly as they could to get everything put in place."

Davis called the Pawlenty campaign the next morning. He was in.

"They were pretty happy that I said yes."

Kevin Diaz is a correspondent in the Star Tribune Washington Bureau.