Buttigieg's once tiny campaign now has more than 250 people on staff, an aide said Friday, making the South Bend, Indiana, mayor's campaign more representative of a top fundraising candidate. Buttigieg's operation is flush with cash after raising what is expected to be the most of any other 2020 Democratic candidate in the second quarter.

Buttigieg started exploring his presidential bid in January with four employees. Months after that soft launch, the mayor has 57 people in Iowa, 39 people in New Hampshire, 13 people in Nevada and 26 people in South Carolina, the Buttigieg aide said. By the end of the third fundraising quarter, Buttigieg plans to have more than 90 people in Iowa, more than 60 in New Hampshire, 30 in Nevada and South Carolina and 20 in California, the aide added.

The massive growth -- Buttigieg only surpassed 100 staffers on the payroll in mid-June -- tracks with the mayor's jump from a largely unknown Democrat to a top tier candidate in the 2020 race . But it also represents a feeling inside the Buttigieg campaign that the mayor's $24.8 million haul from April to June will continue into the second half of 2019, making it possible to sustain such a massive operation.

Buttigieg, in multiple conversations with reporters and interviews with CNN, acknowledged the fact that a burst of momentum in a presidential race does not mean long term success.

"Now the challenge for us is to make sure that we're really reaching everybody," Buttigieg told CNN's David Axelrod in an interview that aired Saturday. "And that we have the kind of ground organization it takes to actually win."

But, Buttigieg added, "It's a great problem to have."

While Buttigieg's operation and campaign bank account have grown significantly over the last month, his standing in the polls has not.

Buttigieg, after polling as high as 10% in a late April in a Quinnipiac University poll , has consistently polled nationally between 4% and 7% in more recent polling, including a CNN poll released earlier this month that found the mayor at 4% nationally.

Buttigieg has largely dismissed the lack of growth in the polls, telling reporters that he believes his fundraising haul proves he has a message that, once voters hear from him, will resonate. He also told CNN that he does not believe he is a candidate that only appeals to people able to donate to campaigns.

"What we know is, for all of the success that we've had early on, there are still a great many Americans who haven't heard of us or don't know much about me and my campaign," Buttigieg said. "So what it tells you, we've got a lot of upside out there, but we've got to go introduce ourselves."

He added: "There is going to be a lot of noise in the polls over the next few months, but we're primarily concerned with the things that are under our control and the biggest of that is how we use these resources in order to fortify our base and get known better and better."

Buttigieg has also followed up the strong fundraising quarter with a burst of travel, especially to Iowa. After spending the first weekend in July in Iowa, Buttigieg is slated to spend the rest of July's weekends in the Hawkeye State.

Buttigieg's campaign began in a small office in South Bend, the small city where the mayor was born, raised and now represents as mayor. Shortly after he caught significant momentum after a widely lauded appearance at a CNN town hall, Buttigieg's team moved into an office five times larger than before comprised of two suites in downtown South Bend.

Over time, however, even that office proved too small and the mayor's team moved yet again, this time to another office building where they now occupy an entire floor in downtown South Bend.

"The whole idea of raising those dollars is to put them to work on the ground," Buttigieg told CNN on Friday in New Hampshire. "Part of what we see as an opportunity and a challenge is that we've got to grow very quickly. The trajectory of this campaign has been faster frankly even than we would have guessed in January. That's a very good thing. But it means now as the season, especially this quarter upcoming when we really lay in that infrastructure."

Staffing up

The staffing process in certain states, especially South Carolina, has been a long time coming for Buttigieg, too, despite the fact that the mayor began telling reporters and voters in the state that he was on the cusp of announcing a major operation for months.

Buttigieg told CNN in early May that he was "about to announce our on-the-ground staff. Two weeks later, as he campaigned in Florida, Buttigieg reiterated that he was on the verge of announcing a South Carolina staff.

"Obviously it's an announcement you only get to make once, so we want to make sure that we're in good shape to do it," he said.

Buttigieg now appears to have a sizable staff on the ground, but a campaign aide told CNN on Friday that the staff still does not have a state director, a key position in each early nominating state.

"I still believe it is very early in the campaign," Steve Benjamin, the mayor of Columbia, South Carolina, told CNN. "We are right around the time where we are having some defining moments - debates, fundraising numbers -- but several of the campaigns have had fully staffed operations [in South Carolina] for several months."

The growth comes months after Buttigieg self-diagnosed his problem in South Carolina, telling top aides after events in early May that there were far too few black voters in his audiences, considering 60% of the state's Democratic primary electorate were black in 2016.

Buttigieg has been proven right, as he has struggled to garner any black supports in South Carolina or nationwide. His events remain predominantly white and polls have shown Buttigieg with little to no support in the black community.

Buttigieg's struggles in South Carolina have been evident to some of the state's Democratic power brokers, but most believe it is early enough in the process for the mayor to show he is serious about competing in the state.

Benjamin and Buttigieg have known each other for years through the U.S. Conference of Mayors. Benjamin said the two have talked about what is needed to succeed in South Carolina and that Buttigieg has been receptive to his advice.

"I have encouraged people to see his heart," Benjamin said. "More and more people who meet Pete, they like him."

But the initial lack of an operation has been felt by top Democrats, like Don Fowler, the former national chair of the Democratic National Committee and a top power broker in the state.

"He has been here a lot. He has a good presence here," said Fowler. "But in terms of his ground organization, I don't know who is in charge."

Fowler added: "He is competitive. His message is clear. I think people appreciate how smart he is. ... Whether or not he can jump to the top is still out."