News that Donald Trump had raised a paltry $3 million since he became the presumptive Republican nominee in early May—and now has less money in his campaign bank than Ben Carson—has had Democrats rejoicing over the past few days. Their excitement was only heightened on Tuesday when Trump shot an email off, targeted at small donors, promising to match any contribution to his campaign between $1 and $2,700 that they made in the next two days.

“This is the first fundraising email I have ever sent on behalf of my campaign,” the mass email bellowed. “That’s right. The FIRST ONE.” (It wasn’t quite the first one.) “And I’m going to help make it the most successful introductory fundraising email in modern political history by personally matching every dollar that comes in WITHIN THE NEXT 48 HOURS, up to $2 million!”

Democrats greeted the letter, quite reasonably, as a sign of Trump’s growing desperation. But it could mean something else entirely: that Trump has finally resigned himself to doing what he should have done from the start of his campaign, and turn his ardent middle-class support into a jackpot of small donations.

That said, some of his most loyal fans may still think twice before sending money to a politician who, just a few months ago, was promising to “self-fund” his campaign. Now, however, Trump has little choice but to beg. Charles Spies, a prominent Republican election lawyer who has advised super PACs from Mitt Romney’s Restore Our Future in 2012 to Jeb Bush’s Right to Rise in 2016, estimates that Trump needs at least $500 million to run a barebones campaign against Clinton. He’ll have trouble drumming that up from the usual suspects. Donors like Kansas industrialists Charles and David Koch are sitting out the presidential race, as is hedge fund manager Paul Singer. Moreover, the constellation of Trump super PACs are in disarray, according to Politico.

He’ll no doubt be able to secure some $100,000 donations, from the wealthy conservatives who will still answer his calls. But most of all, Trump needs a whole lot of people to send in $25 skimmed off the top of their paychecks each month.

If Trump can build a Bernie Sanders-like small-donor machine, it would mean more than just a chance to get cash flowing regularly into his coffers. It would also be a positive thing he could do for his party. Returning the GOP to its Reagan-era roots as the party for small donors might even placate some of the stalwarts who have watched in anguish as Trump tears the GOP apart.

Hard as it is to remember now, the Republicans once relied heavily on small donors. Ronald Reagan depended on direct-mail blitzes to fund his campaigns. When he won re-election in 1984, he received 60 percent of his funding from small donors, a record high. This continued through 2000, when George W. Bush got a whopping 72 percent of his funding from small donors, considerably more than Al Gore. According to The New York Times, “Republican officials bragged of his support from more than 600,000 donors contributing an average of about only $100 each, far outpacing the Democrats.”

The landscape shifted in 2004, when Democrat Howard Dean leveraged the internet to finance his long-shot presidential bid. Four years later, when Barack Obama won the White House on a groundswell of support from people who donated less than $200, the Democrats established themselves as the party of small donors.

As the Democrats veered one way, the Republicans went another. In 2010, after Citizens United opened the floodgates for special interests to spend unlimited sums on political campaigns, President Obama decried the decision in his State of the Union speech. Republicans, on the other hand, went whole-hog with big money. Wall Street donors rallied behind Mitt Romney in 2012, the same year his infamous “47 percent” remarks at a swanky Boca Raton fundraiser solidified the impression that Republican politicians would pander to wealthy donors in office, rather than advocating for average citizens. Romney raised $80 million from small donors. Obama raised $234 million.

The 2016 Republican primary was no different. Mainstream Republicans candidates spent little time courting small donors. Only 6 percent of Jeb Bush’s contributions came from them, and only 27 percent of Marco Rubio’s. That is a liability in a political climate where most Americans believe that money in politics should be checked—and a practical problem when Democratic politicians like Sanders are raising 60 percent of their funding the small way.

The advantages to building a finance operation grounded in small donations are more than financial. You get to be on the right side of public opinion: Voters distrust big money in politics, and they almost all agree that the government should impose limits on how much the wealthy can donate to campaigns. Wooing small donors also garners you a base of passionate people who are literally invested in your cause, making them more likely to canvass for you, turn out for you, and give money in future elections. Moreover, their money goes further than a super PAC’s, because it goes straight into campaigns—and campaigns get lower rates for television airtime, which Trump badly needs.

How much could Trump rake in from a four-month barrage of desperate appeals, from now to November? In short, a lot. Other Republicans this year haven’t been a total bust with small donors; Ben Carson raised 58 percent of his contributions from them. And according to Open Secrets, Bernie Sanders’s campaign—the gold standard for small-donor-rustling—had raised almost $133 million in small individual contributions through May 23, much of it after his campaign took off this past winter. “Bernie Sanders was a backbench senator,” says Bob Biersack, a senior fellow at the Center for Responsive Politics, a research group that tracks money in elections. “He was obscure in the larger political conversation even a year ago and he raised hundreds of millions of dollars.”

Trump, running in the general election against a Democrat rank-and-file conservatives loathe, should theoretically be able to draw in even more. “There are millions of people who voted for him in the primary,” Biersack notes. “They are receptive to his message. If he set up the infrastructure and showed them how important it was, there is nothing that would prevent him” from bringing in bundles of small donations. “But Trump has got to commit to that. He would have to work to light the match that would ignite the enthusiasm.” And there seems little doubt that he will—one all-caps, “first ever!” appeal at a time.