Macey Meyer never considered herself the type to donate to a presidential campaign. Then she watched the first Democratic presidential primary debates.

The 26-year-old restaurant server from Maple Grove felt energized as she listened to nearly two dozen candidates tangle over a range of policies and visions. She opened a browser window and contributed $3 to U.S. Sen. Elizabeth Warren's campaign. In the minutes that followed, she clicked "Donate" 10 more times — to 10 different candidates.

"I think it's important to vote with your dollar," Meyer said. "Even though 3 to 5 bucks isn't much, if a lot of people had that mind-set, it is a lot. It adds up."

Meyer is right about the math. As the money chase increasingly adapts to technology, millions of small-dollar donors like her poured more than $200 million into Democratic presidential primary campaigns using the online donation platform ActBlue in the first half of the year, according to the Center for Public Integrity. Often the money was doled out in increments equal to less than the cost of a cup of coffee.

In Minnesota, about 55,000 people gave a combined $4.7 million-plus to Democratic presidential hopefuls via ActBlue in the first half of the year, a Star Tribune analysis of Federal Election Commission filings found. That represents a big spike from this point in the 2016 election cycle, when just 18,000 state residents had made an ActBlue contribution to a Democratic presidential campaign.

It's not just Democrats courting small-dollar donors on their laptops and smartphones. Earlier this year, Republicans launched WinRed, an online fundraising hub meant to be the right's answer to ActBlue. Minnesota Republican Party Chair Jennifer Carnahan said she expects the platform to be a "game-changer." She hopes the technology will further accelerate what she described as a surge in small-dollar donors to the state GOP since President Donald Trump's election.

Trump is not expected to face meaningful primary competition. But committees helping Trump's 2020 re-election effort have raised tens of millions of dollars from donors giving $200 or less. Carnahan noted that such donors accounted for more than 60% of direct contributions to his campaign, a stark increase from previous GOP presidential campaigns.

"He's energized them, he's created enthusiasm and excitement, he's given people hope across the country," Carnahan said of the president. "And he's tapped into a lot of new voters and new donors."

But the role of small donors in the Democratic primary has been especially pronounced this election cycle, because of the large number of candidates and new qualification rules the Democratic National Committee created for nationally televised debates.

"People are plugged in, in more ways than one and much earlier than they have been in the past," Minnesota Democratic-Farmer-Labor Party Chair Ken Martin said. "We've seen a record outpouring of small donor contributions. More than anything it is a sign of enthusiasm and excitement for the upcoming races."

Democratic contenders had to secure at least 65,000 unique donors to make the stage for the first pair of debates, held in June and July. For this month's debate, set for Sept. 12, the bar was raised to 130,000. "The thresholds have helped to spotlight the power of online fundraising, obviously, and to encourage campaigns to do it," said Tim Lim, a Democratic strategist who worked on the presidential campaigns of Hillary Clinton and Barack Obama. "The argument is, 'Give me a chance to be heard.' "

In Minnesota, U.S. Sen. Amy Klobuchar's presidential campaign appears to be contributing to the boost in engagement. Klobuchar has spent heavily on digital ads targeting donors in her home state. And it's paid off: More than a third of Minnesota ActBlue donors gave to her campaign, sending a cumulative $2.6 million her way.

But the crowded and divided Democratic candidate field has also introduced a new phenomenon that Lim describes as a "big surprise" to many in the fundraising world: Undecided Democrats like Macey putting their cash behind multiple candidates simultaneously. Nationwide, about 20% of small-dollar donors contributing via ActBlue gave to more than one presidential candidate. Even Klobuchar, who held a commanding lead over rivals in Minnesota small-dollar donors and fundraising totals, saw 17% of contributors give to multiple rivals.

"You normally would never see this. I can't even think of an instance when you saw this really in play," Lim said. "There wasn't a Hillary Clinton-Barack Obama donor in 2007 or the 2008 primary."

While Lim credits the debate thresholds with fueling the increase in donors, he said the trend may also reflect a struggle among Democrats to choose a favorite in a crowded race.

"It's clear that there isn't a really strong front-runner that's going to be able to close out the field," Lim said.

Minnesota resident Angela Bernhardt is one of those small-dollar donors with "multiple favorites." The self-described political independent from Medina made 26 separate contributions ranging from $1 to $3 to 15 Democratic presidential campaigns through June 30. That figure has only increased throughout the summer. While Bernhardt has identified a few personal front-runners, including Warren and Montana Gov. Steve Bullock, she said her main priority is helping Democrats defeat the president in 2020.

"I have given, I think, to everyone," she said. "I'd say anyone but Trump."

Campaign merchandise offered to thank contributors can also be a motivator. Bernhardt was one of 4,000 donors who gave to Klobuchar and another Democrat. "I'm sure it was to get a bumper sticker," she said of her $2 donation to her home-state senator.

Some donors to multiple candidates see their contribution as a way of showing support for specific issues or policy platforms. Meyer, a first-time donor, said she gave $5 to former Washington Gov. Jay Inslee's now-folded presidential campaign because she liked his spotlight on environmental issues.

"I realized he's not going to win, but I think his message is really important by focusing his entire campaign on climate change," she said.

While the uptick in small-dollar donors may suggest enthusiasm and engagement, the surge in giving is by no means organic. Campaigns are spending sizable sums on digital ads to get people to donate. Pleas for cash, made via Facebook, text and e-mail blasts, are tailored to elicit a response, targeting potential voters based on everything from issues to ZIP codes.

Some analysts expect that, as the field narrows, donors in Minnesota and beyond will begin concentrating their contributions on a smaller selection of candidates.

That's already been the case for Neil Hamrin, a retired math teacher from Eden Prairie who donated to nine candidates in the first half of 2019.

"Earlier on, I felt it was important to let as many people with as many points of view speak and see what would resonate," Hamrin said. "I have not given to nearly that wide a field lately, nor will I. I think it's time to sharpen the focus."

"I think it's critically important to get some sane people back at the top of our national government, and I need to do what I can in that regard," he said. "What I can do isn't very much other than giving my approval, that is, my name and some money."