– The dog days of summer could be crucial to Sen. Amy Klobuchar’s presidential hopes.

Polling consistently in the low single digits, far behind the leaders, the Minnesota senator has taken out a slew of Facebook ads and dispatched hometown supporters across the Twin Cities pleading for small dollar contributions to reach a minimum threshold of individual donors to qualify for the critical third round of debates in September.

The Democratic National Committee has given candidates until Aug. 28 to meet its fundraising and polling criteria for the Sept. 12-13 debate in Houston. To be included, candidates must reach at least 2% support in at least four national or early primary state polls from the end of June to the end of August. And they must amass at least 130,000 individual campaign donors.

To date, Klobuchar’s campaign has not hit either mark.

“We’re within striking distance,” said Justin Buoen, Klobuchar’s campaign manager. “I’m incredibly confident we’re going to get there well in advance of the deadline.”

Five rivals, generally seen as the contest’s front-runners, appear to have already qualified: Joe Biden, Bernie Sanders, Elizabeth Warren, Kamala Harris and Pete Buttigieg. Klobuchar could be on track to reach the polling requirement soon. She has tallied 2% in three polls since June 28. But in a new NBC/Wall Street Journal national poll out Friday, Klobuchar registered at only 1%, trailing entrepreneur Andrew Yang and former Texas congressman Beto O’Rourke. Worse, a new Fox poll in South Carolina had her at less than 1%, behind Yang, former Maryland congressman John Delaney and New Age author Marianne Williamson, who each registered at least a single digit.

Klobuchar’s campaign won’t say how close she is to reaching 130,000 donors. But her fundraising message in recent weeks has increasingly pivoted toward achieving that goal.“We need 130,000 unique donors to qualify for the DNC’s fall debates, and we must hit this goal to stay on pace. Donate $2 now and we’ll send you a free bumper sticker,” reads a Klobuchar fundraising solicitation that has been popping up as sponsored content in Facebook and Instagram feeds.

Political analysts say that in order to make the all-important cut and stay on the debate stage, marginal candidates like Klobuchar are being forced to spend money on online ads targeting large numbers of small-dollar donors, rather than building broad support among voters.

“I’d be real curious to know how much of her spending is going into acquiring those 130,000 donors,” said Scott Cottington, a Republican fundraiser based in St. Paul. “If you’re plowing all your small donor donations back into prospecting for more, you’re not going to be netting much from it.”

At the same time, failure to secure a spot on the debate stage in September, when many voters are just starting to tune in, would constitute a serious blow to any candidate. Needing to avoid irrelevance before the calendar flips to 2020, Klobuchar is being forced to dedicate less of her campaign muscle to persuasion and more to simply qualifying for debates.

No votes will be tallied until next February’s Democratic caucuses in Iowa, a crucial Midwestern battleground state for Klobuchar. But race watchers expect the third debate’s higher bars to force the first major narrowing of the large Democratic field, which has swelled to two dozen candidates.

“It’s going to be devastating for anyone who doesn’t make that debate,” said Ken Christensen, a longtime Democratic fundraiser. “It sends a message about your campaign. It affects your fundraising, it affects any positive momentum you might have.”

Some Democratic contenders have shown an aptitude for assembling legions of small donors. It’s increasingly important as numerous candidates, including Klobuchar, have sworn off donations from federal lobbyists and corporate PACs. “The last couple years changed everything,” Christensen said. Special election candidates like Georgia’s Jon Ossoff and Alabama’s Doug Jones “showed conclusively that small-dollar donors can make a big difference.”

Sanders, the Vermont senator who also ran for president in 2016, reported donations from 150,000 individuals in the first 10 hours after launching his campaign in February. He’s since exceeded that several times over.

“It certainly privileges candidates who have national name recognition, like Biden and Sanders,” said Guy-Uriel Charles, a professor at Duke Law School who teaches and writes about politics and related legal issues. “It also privileges candidates who come from states with existing strong Democratic donor networks” — like California’s Harris and Massachusetts’ Warren.

Buttigieg, the mayor of South Bend, Ind., posted the highest fundraising total for the second quarter of 2019 — more than tripling his first-quarter haul. He boasted neither of those assets, but Charles said Buttigieg was able to leverage “a compelling personal story” to break through.

“Mayor Pete captured people’s imaginations, and look what it did for his fundraising,” said Charles, who previously taught at the University of Minnesota Law School. “For whatever reason, Senator Klobuchar has not been able to break out as well as she should.”

Klobuchar is expected to release her second-quarter fundraising totals on Monday. Between Feb. 10, when she got in the race, and March 31, the end of the first quarter, she raised $5.2 million. By early May she reached the individual donor threshold of 65,000 needed to participate in the first two debates, meaning she is guaranteed a spot in the second Democratic debate in Detroit on July 30-31.

But it’s the third debate that will really clarify who’s a contender and who isn’t. Klobuchar is far from the only serious candidate who’s having to push hard to clear the bar; she’s in the same boat as fellow senators like Kirsten Gillibrand, Cory Booker and Michael Bennet, as well as current and former governors Jay Inslee and John Hickenlooper.

And so e-mail fundraising solicitations from the Klobuchar campaign are coming at a fast clip. “How well we do now will decide who will have the momentum to keep fighting, who will make it into the fall debates and who will take on President Trump in 2020,” read an appeal from Julia Kennedy, Klobuchar’s deputy campaign manager.

The push for large numbers of small donors also has kept Klobuchar, a force in state politics, plowing familiar ground. In early June, she spent a day campaigning in Duluth and Fargo — two small cities where voters will have no say whatsoever in the all-important early weeks of the Democratic nominating contest.

And in the first weekend in July, according to a handful of reports on Twitter, Klobuchar campaign workers were out soliciting small donations at various Twin Cities venues.

Matt Keliher, a St. Paul bookseller, tweeted out the plea he heard at the St. Paul Farmer’s Market: “Four quarter donation gets Amy debatin’.”