When Amy Klobuchar discusses campaign fundraising in public, it's usually for laughs.
She routinely makes a self-deprecating joke about hitting up donors during her first run for the U.S. Senate more than a dozen years ago.
"I finally ended up just calling everyone I knew in my life. And I raised what is still an all-time Senate record: I raised $17,000 from ex-boyfriends. I did that," Klobuchar said in the latest recounting this week at the "We The People" Summit in Washington. "And, as my husband has pointed out, it's not an expanding base."
Expanding her donor base is vital for Klobuchar's White House bid. She's likely to be dwarfed by the impressive hauls that Vermont Sen. Bernie Sanders, California Sen. Kamala Harris and former Texas U.S. Rep. Beto O'Rourke have generated so far.
Klobuchar told the "We The People" audience that she won't be discouraged.
"I am someone that has gotten everywhere I got when I was running against someone who had a lot more money than me and a lot more connections than me," she said. "And I did it because I have grit."
MPR News analyzed fundraising data for Klobuchar since 2005. That includes money she's raised for her Senate campaign, for a separate federal account and for her Follow the North Star leadership fund.
The combined total tops $33 million. Only her first Senate campaign was against a well-funded challenger, so Klobuchar hasn't had to quickly accumulate the $10 million or more it takes these days to run a truly competitive race.
But where the money comes from is also telling.
Only about 19 percent of Klobuchar's contributions have come from people who gave a couple hundred dollars or less during a campaign cycle. They're what's known as unitemized or small-dollar contributors.
In the presidential campaign, donors like that have become the most sought-after.
"They have the ability to continuously give again and they won't even get near their cap," said Jonathan Mantz was national finance director during Hillary Clinton's first run for president and then an adviser to a SuperPAC supporting her 2016 run. He's on the sidelines of this race.
He looks at it this way: A campaign is better off getting $28 from 100,000 donors than the maximum $2,800 donation from 1,000 contributors.
"Just fundamentally, the math enables you to have a much higher potential ceiling of fundraising," he said.
To be successful in the small-dollar world, Mantz said candidates need a magnetic message and ability to keep those donors engaged without leaving the impression it's only about the money.
"If every email or every message concludes with 'I need your money,' ultimately you're going to lose that interest. They don't just always want to be part of a fundraising campaign," Mantz said. "They want to be part of a more lofty campaign."
But a focus on small donors is expensive for campaigns. For every solicitation that goes out, many won't get opened and even fewer will result in a donation.
"You're talking about 2-3 percent is a good day," Mantz said. "So that's a lot of emails to get 2-3 percent support in every message that goes out."
Klobuchar has small donors to turn to. Retired social worker Jerry Manlove of New Brighton is one.
"I gave her 25 per month," he said. "I'm going to add another 10 to that."
Manlove has been a reliable giver for years. According to federal records, his bite-at-a-time contributions added up to $1,300 for Klobuchar's Senate campaign.
He said he likes her moderate approach to issues compared to other presidential candidates he fears will be pegged as extreme by Republicans.
But Manlove is spreading his money around: "I've already signed up to give Joe $50 a month."
As in former Vice President Joe Biden, who isn't a declared candidate.
Mary Groeschner of La Crosse, Wis., has also been a regular Klobuchar donor, typically $50 per month during the Senate campaigns.
"When I decide to support a candidate, I do it consistently throughout the race," she said.
Groeschner is a retired financial counselor originally from Minnesota who says she's fond of Klobuchar, although has some concerns about her when it comes to environmental issues.
She hasn't given to Klobuchar or another 2020 candidate yet because she wants the field to shake out some first.
"There are a few, no-way-on-earth people on the list," Groeschner said with a laugh, declining to identify them.
Klobuchar had about $4 million left in her Senate campaign fund at the start of the year. She would be free to transfer a good chunk of that to her presidential effort if she hasn't already.
The Democratic candidates aren't swearing off the major-dollar donors. Many, including Klobuchar, are holding big-buck fundraisers as they travel the country.
The senator's various accounts took in more than $2.5 million from political action committees over the years, a decent share of that from PACs tied to corporations in the financial, medical and technology sectors.
But for her presidential campaign, Klobuchar is drawing the line on some donations, as she told supporters on Facebook recently.
"This is a grassroots campaign," she said. "I'd love for you to join us and make a donation. It can be small. It can be in any amount. We want your help. I am not taking corporate PAC money. I am not taking federal lobbyist money. I am taking money from you."