Des Moines (CNN) Pete Buttigieg , a candidate who once had more momentum than any Democrat in the 2020 race , has plateaued.

After using a well-reviewed appearance at a CNN town hall in March to introduce himself to Democratic voters, the South Bend, Indiana, mayor rocketed from relative obscurity to the upper echelon of the once growing field of Democrats vying to take on President Donald Trump.

Months removed from that burst, though, Buttigieg's polling has largely remained static, with middling single-digit numbers that consistently land him behind candidates like Massachusetts Sen. Elizabeth Warren, Vermont Sen. Bernie Sanders and Vice President Joe Biden -- even as he rakes in dollars from big donors around the country.

The way forward, Buttigieg's team believes, is by not only spending that money to hire top talent, but also by creating a unique organizing plan that matches the mayor's own distinctive story. While the mayor rose to national prominence without much of an organization, getting him past this point will require committed organizing, aides argued.

And Buttigieg has spent the most time focused on one state: Iowa, where the mayor made his 10th trip on Wednesday.

"Iowa is central," Buttigieg told CNN in an interview. "It's the first chance to really prove everything we've been saying about how organized we are about the idea that what we have to say is winning with people across a range of voters and caucus-goers."

The campaign has moved quickly in recent weeks to leverage a growing number of all-in volunteers to expand his reach, profile and support in a state that will likely be crucial to his path to the nomination.

Buttigieg has seen plenty of success over the last three months, but his overall standing in the race hasn't followed the money or early attention that has rolled in, a fact that has not gone unnoticed by his top campaign operatives.

He raised more money than any other candidate from April to June of this year, using it to grow his once four-person shoe-string campaign operation into an over 300-staffer behemoth nationally. And the mayor has turned in two well-received, albeit not breakout, debate performances.

His once-thin policy portfolio has also expanded on a seemingly weekly basis, from a major foreign policy address and a sweeping proposal to tackle what he views as systemic racial inequities to a newly released proposal to spur investment and growth in rural regions of the country.

To many inside top Democratic circles, it is astounding that Buttigieg has even made it this far.

Buttigieg, once a small city mayor with no national profile, came into the campaign with built-in disadvantages when compared to people like Biden, Warren and Sanders -- three Democrats with far more name recognition and reliable donor bases. And he's become far more of a household name in Iowa, where only 26% of Iowa Democrats likely to attend the caucuses didn't have an opinion of him in June, according to the CNN/Des Moines Register/Mediacom survey, a number that was 73% in March.

But the mayor is far from satisfied with just grabbing attention and having a singular "moment" in the race. As he told a voter in South Carolina over the weekend, he's not running to lose.

"We're in it to win it," he said when asked if he would consider a vice presidential slot.

Staffing up

Buttigieg's top aides, while admitting that their polling has flattened in recent months, tell CNN that they aren't currently concerned but will be if this continues in the coming months.

"I would be more worried if we're having this conversation 45, 60 days from now," said Jess O'Connell, Buttigieg's newly hired senior adviser who previously served as the CEO of the Democratic National Committee. "I feel good about (his current standing), but I think we have work to do."

Buttigieg's once four-person presidential campaign has ballooned in recent weeks . The campaign recently crossed the 300-person threshold and advisers hope to have 90 people in Iowa, more than 60 in New Hampshire, 30 in Nevada and South Carolina and 20 in California by the end of September.

"We're about to level this up to a full-scale, real presidential operation," O'Connell said, adding that Iowa -- because Buttigieg is a fellow Midwesterner -- will be central to his late-year push. Buttigieg's trip to Iowa on Wednesday was his 10th as a candidate.

And operatives in the state -- some who once complained about Buttigieg's lack of an organization -- have felt that increased presence.

"On the ground, his people are everywhere," said Laura Hubka, the chair of Howard County Democrats, whose county went for President Barack Obama by 20% in 2012 and Trump by 20% in 2016, a flip that represented the biggest flip of Obama to Trump support in the nation.

She said Buttigieg's organizational blitz has become hard to miss over the course of the last month, and that it's starting to rival the top operations in the state -- something she said, anecdotally at least, was reflected in the enthusiasm when he personally showed up at events as well.

Given that, however, she did have a looming, unsolicited observation.

"I just don't know why the polls don't have him higher."

Photos: Former presidential candidate Pete Buttigieg Photos: Former presidential candidate Pete Buttigieg Pete Buttigieg, the former mayor of South Bend, Indiana, poses for a portrait at his office in December 2018. Hide Caption 1 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg was an intelligence officer with the Navy Reserve from 2009 until 2017, and he served in the war in Afghanistan. Hide Caption 2 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg thanks supporters after he was elected mayor in 2011. Buttigieg was born and raised in South Bend and went on to attend Harvard College. He later became a Rhodes scholar. After a three-year stint at the consulting firm McKinsey and Company, Buttigieg came back to Indiana and lost a race for state treasurer in 2010. Hide Caption 3 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg listens to a question during a news conference announcing an interim police chief in March 2012. Hide Caption 4 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg paddles a raft during the East Race Waterway in July 2013. Hide Caption 5 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg delivers his State of the City address in February 2014. Hide Caption 6 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg is welcomed home in September 2014 after serving a seven-month tour of duty in Afghanistan. Hide Caption 7 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg speaks in November 2014 during a presentation ceremony for a newly redeveloped area in South Bend. Hide Caption 8 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg speaks out about the Religious Freedom Restoration Act that was signed in Indiana in March 2015. Buttigieg and other critics of the legislation, which was signed into law by then-Indiana Gov. Mike Pence, contended that individuals and businesses could use it to discriminate against the gay community on the basis of religion. Pence later signed an amendment that was intended to protect the rights of LGBT people. Hide Caption 9 of 28 Photos: Former presidential candidate Pete Buttigieg The State Theater in downtown South Bend shows its support for "Mayor Pete" after Buttigieg came out as gay in June 2015. Hide Caption 10 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg's name is Maltese and roughly translates to "lord of the poultry." His husband, Chasten, tweeted a list of possible pronunciations in 2018 that included "boot-edge-edge," "buddha-judge" and "boot-a-judge." Hide Caption 11 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg speaks at a debate-watching party in Chicago in September 2016. He was stumping for Democratic presidential candidate Hillary Clinton. Hide Caption 12 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg speaks during a Democratic National Committee forum in February 2017. Hide Caption 13 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg greets supporters during the DNC forum in February 2017. He was campaigning at the time to be the committee's chairman. Hide Caption 14 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg walks with Facebook CEO Mark Zuckerberg, a personal friend, who was visiting South Bend in April 2017. Hide Caption 15 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg appears on "Late Night with Seth Meyers" in June 2017. Hide Caption 16 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg kisses his husband, Chasten, after they were married in South Bend in June 2018. Hide Caption 17 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg announces in December 2018 that he would not be seeking a third term as mayor. Hide Caption 18 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg talks with a reporter in downtown South Bend in January 2019. Hide Caption 19 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg speaks to reporters in Washington after announcing his presidential ambitions. Hide Caption 20 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg speaks during the US Conference of Mayors in January 2019. Hide Caption 21 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg speaks during a campaign stop in Ankeny, Iowa, in February 2019. Hide Caption 22 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg signs copies of his book "Shortest Way Home" in February 2019. Hide Caption 23 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg speaks on stage during the South by Southwest Festival in Austin, Texas, in March 2019. Hide Caption 24 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg answers questions from supporters during a fundraising event in West Hollywood, California, in March 2019. Hide Caption 25 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg and former Vice President Joe Biden talk during a break in the first Democratic debates. Hide Caption 26 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg takes part in CNN's Democratic debates in July 2019. Hide Caption 27 of 28 Photos: Former presidential candidate Pete Buttigieg Buttigieg announces the end of his presidential campaign at an event in South Bend, Indiana, in March 2020. Hide Caption 28 of 28

Buttigieg echoed his team in saying at least at this stage in the race, he's not worried about the polling, beyond the fact "they put us in a tier of candidates beyond most of the competition." Indeed, in a field of nearly two-dozen candidates, Buttigieg falls in the top 10 in both polling and fundraising, which qualifies him for the next round of debates in September.

Instead, he views the current moment as firmly in the second phase of a three-phase campaign plan -- the part where the money and national attention is funneled into a well-honed campaign machine.

"This is the stage where I think the campaign is really to be won, because now we have people on the ground forming the interpersonal relationships that are the real stuff of good politics, especially in a place like Iowa," Buttigieg said.

Therein lies a central organizing strategy for the campaign, one that prioritizes personal relationships over more traditional techniques.

Make it personal

Top Buttigieg advisers believe that because their candidate hasn't been a national name for years, it will take longer for possible supporters to get to know him. To do that, they said, they will urge their paid organizers and volunteers to tap personal networks more than asking them to do cold calls to people they don't know.

This was on full display Tuesday night at a suburban home about eight miles away from the state capitol building in Des Moines, when 18 Buttigieg volunteers were getting their first taste of the campaign's emphasis on relationships.

"We want to rethink how you guys think about campaigning and how you think how a campaign is done," Shannon Sankey, one of the campaign's organizers, told the group assembled in scattered chair across a kitchen with a ring of a dozen "Pete 2020" or "Boot-Edge-Edge" signs taped on the walls around them. "This is just the beginning of how we're going to do this."

Door knocking and phone banking keyed off of voter files are certainly central components of the campaign's operation, advisers say, but at a time when nearly two dozen campaigns have driven many Iowans to ignore numbers they don't know, it's the personal relationships that get calls answered.

During the 90-minute session, each volunteer was asked to write down three to five friends or relatives on a sheet of paper who they thought might be interested in Buttigieg. Then three to five more friends, or acquaintances who weren't as politically involved. Then they got on the phone and moved to wrangle new recruits -- either to attend Buttigieg's Iowa appearances the next day, or to attend a future house party, or even just to receive links to information about Buttigieg and his campaign.

The strategy is, to some degree, simple: Leverage relationships. Rely on the friends and relatives to preach the book of Buttigieg. Lean on supporters who are all in to bring their social circles on board with them.

The Des Moines meeting was one of dozens that have taken place in all corners of the state in recent weeks.

O'Connell, who in 2008 was a senior aide on Hillary Clinton's failed presidential campaign, said the Buttigieg strategy is most similar to then-Sen. Obama's campaign in 2007 and 2008, a sizable claim given that campaign would go on to remake Democratic organizing for years to come.

"I do think there are, for us, some similarities to Barack Obama in the 2007/2008 race in the sense that he had to widen the electorate and expand the sort of base in Iowa," O'Connell said. "Pete's lane is going to require his own coalition to win and, again, that is why we are taking the extra time with people in a different kind of way."

The Buttigieg campaign sees multiple upsides with this organizing strategy. Enlisting friends to call friends creates a multiplier effect to a paid staff in Iowa that is still growing.

It gets voters on the phone more reliably than cold calling, but it also expands the contact universe -- something Buttigieg's campaign, with a focus on rural counties, some of which flipped from supporting Obama to heavily favoring Trump, has sought to capitalize on, with Buttigieg's message of a Midwestern mayor who regularly talks about his faith.

"It's everything," Buttigieg said of the role those volunteers will play in whether his campaign is a success. "You need to have that that kind of army of people who can spread the message, and often they find ways that I wouldn't have even thought of to describe what's at stake, and why this candidacy matters."

Pam Kenyon, a Democrat who said she has never actively volunteered for a campaign before, is to some degree the prototype for the rapidly expanding campaign. She attended a house party in May in Dallas County where she knew nobody and was curious to hear what Buttigieg had to say.

By the time he was done speaking, she was hooked. She signed up to phone bank. And then did it again. And again. And attended another house party. Before long, she was spreading the word to everyone in her circle.

"It was sort of like an addiction in a way of wanting to be with such a refreshing human being who seems to really care about what's happening," Kenyon told CNN.

Asked about the broader Democratic field, Kenyon ticked through the names and said positive things, noting she wished Biden would've run in 2016. But when it came to Buttigieg, she ticked through a handful of his policy proposals and concluded: "He is just better."