2020 Democratic hopeful South Bend Mayor Pete Buttigieg brought in an eye-popping $25 million during the second quarter of the presidential campaign, outpacing the likes of fundraising powerhouse Sen. Bernie Sanders. The numbers marked a payoff for an unconventional campaign schedule that focused on national media interviews and fundraisers, all designed to make a political newcomer into a star.

But a number of fresh polls suggest that strategy isn't yet translating on the ground, as the mayor hovers around the low single digits. A CNN survey taken after the first Democratic debate found Buttigieg actually losing ground by a point. And a Quinnipiac University poll released Tuesday, also showed Buttigieg losing support by six points.

With a significant amount of money in the bank, the Buttigieg campaign is now shifting course, focusing the summer getting back to the basics of retail campaigning, bolstering its presence in Iowa and New Hampshire.

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The second quarter fundraising report "showed we are in the top tier and and we have a top tier campaign, and people are going to start seeing it now over the next couple of months," said campaign spokesman Chris Meagher. "You're going to see Pete doing a lot more retail in Iowa and New Hampshire...more organizing, more neighbor to neighbor contact."

The campaign is aiming to double its staff of 150, and will begin to roll out a number of "bold" policy proposals. "Pete's schedule is going to get more aggressive," said Meagher.

Buttigieg is planning to campaign in Iowa on at least two separate occasions this month, including various stops around the Fourth of July holiday. He will also visit New Hampshire next weekend.

The campaign is also struggling to gain any traction among black voters, a key constituency that figures to make or break Democratic presidential campaigns. The new Quinnipiac University poll displays that Buttigieg received 0% of African American voters' support. At an event in Chicago with Rev. Jesse Jackson on Tuesday, Buttigieg addressed the disparity.

"There's a lot of voters I need to get to know and who need to get to know me," Buttigieg said. "Frankly, they need to see me in action for a longer period of time."

The fatal shooting of a black man by a South Bend police officer in June placed greater scrutiny on Buttigieg, and his management of the fallout garnered public, emotional criticism from his constituents. It also highlighted the fact that while 26% of the residents of South Bend are black, only 6% of the police force is African American. "I couldn't get it done," Buttigieg said in last week's Democratic debate in Miami when asked about the lack of diversity.

"I could walk you through all of the things that we have done as a community — all of the steps that we took from bias training to de-escalation but it didn't save the life of Eric Logan," he said. "And when I look into his mother's eyes I have to face the fact and nothing that I say will bring him back."

Buttigieg's initial rise to stardom signaled that the race for the White House in 2020 might run through green rooms and ballrooms in New York and California rather than living rooms and back yards in Iowa and New Hampshire. Even former Rep. Beto O'Rourke of Texas shifted his approach to include more national television interviews, after failing to gain traction through smaller, more traditional campaign events. With so many candidates in the running, and President Trump continuing to drive news cycles, viral breakout moments are at a premium.

But the South Bend police shooting and the post-debate polls show the perils of relying on a national campaign strategy. And even in a post-Trump era, some old rules of politics may still apply. Or at least, the 2020 campaign will put that to the test.

"It seems as if he is building a top-down operation instead of the ground up," says Democratic strategist and CBSN contributor Antjuan Seawright. "What we all know is, if he wants to strengthen his support, especially with the African American community, he needs to spend some real time and not just talk about it. And I think he will make adjustments now."

Julianna Smoot, a former Obama campaign and administration alum, said Buttigieg's second quarter fundraising total will allow him to expand his campaign's infrastructure and organize staff and volunteers in the early states.

"That is exactly the kind of improvement you want to see and it shows a lot of growth and strength," Smoot said.

Still, with Buttigieg's renewed focus on campaigning, fundraising remains a priority for the campaign.

In the second quarter, Buttigieg headlined more than 70 fundraisers and 20 of those fundraisers were grassroots fundraisers, according to a campaign aide. Buttigieg is scheduled to hold fundraisers in Illinois Tuesday and Wednesday before traveling to Iowa. This weekend, the South Bend mayor is scheduled to travel to Massachusetts, where he has fundraisers in Provincetown and Nantucket and a grassroots fundraising event in Martha's Vineyard.

Sarah Ewall-Wice contributed to this report.