How will the Democratic National Committee deal with the expanding field of presidential hopefuls in their debates? With two dozen or more candidates of significance, the people on stage might outnumber the people in the audiences. The first two debates will get split over two nights, the DNC decided in February, with candidates randomly distributed into assigned slots.

By the time of the third debate, however, the DNC will solve the problem by choking off access to the stage:

To appear in the party’s third debate, which will be broadcast by ABC News and Univision, candidates will have to earn 2 percent support in four party-sanctioned polls between late June and August. In addition, they will have to show they’ve attracted at least 130,000 donors since the start of the campaign, including at least 400 from 20 different states.

That third debate will be held on Sept. 12, with the possibility of a second session on Sept. 13 if there are enough qualifying candidates to require two stages.

As the race now stands, only eight candidates in the field would meet the 2 percent threshold in recent party-sanctioned polls, according to an assessment by FiveThirtyEight, a data analysis website. Many are also struggling to reach the donor requirements.

By requiring a combination of grass-roots donations and polling, Democratic National Committee Chairman Tom Perez is preparing to effectively close off debate access for candidates who cannot grow their popular support or attract a significant base of small contributors.

If the DNC went by the RealClearPolitics aggregate averages, there’d only be seven on stage for the ABC/Univision debate. Beto O’Rourke and Cory Booker would just make the cut, assuming they also meet the donor threshold as well. Amy Klobuchar would just miss the cut, while Kirsten Gillibrand and the only two governors showing up at all in the polling (John Hickenlooper and Steve Bullock) would miss by a mile.

Of course, all of these might benefit from the first two debates and a summer of campaigning, the DNC argues. It might still mean a crowded stage in the fall:

Party officials say the additional two months of campaigning, combined with appearances in the heavily promoted summer debates, could lead to more candidates reaching the new threshold. Officials also point out that no Democratic candidate consistently polling under 2 percent has gone on to win primaries and caucuses since President Jimmy Carter in 1975.

That’s not comforting enough for the one percenters, who argue that the September deadline is too soon for culling the herd:

“I don’t think the D.N.C. should be winnowing the field early in the process,” Senator Michael Bennet of Colorado told Fox News during a campaign swing through New Hampshire.

Some of those who’ve not yet met the donor requirement claim that the system incentivizes candidates to place too much focus on capturing small donors.

“I don’t think it’s a measure of success,’’ said Senator Kirsten Gillibrand, of New York, whose campaign has not said whether she’s met the donor requirement. “I don’t think it’s a measure of electability. I don’t think it’s a measure of quality of candidate.’’

If  it’s not a measure of success, electability, or quality, then why do candidates routinely brag about their donor base and their polling? Or at least some of them do. When they don’t, it’s usually a sign of trouble, as the New York Times pointed out two months ago with Gillibrand’s Q1 disclosure:

Senator Kirsten Gillibrand’s presidential campaign raised $3 million in the first quarter of the year, a spokeswoman said on Sunday, a disappointing sum that ranked her last among the six senators currently running for president.

Ms. Gillibrand, New York’s Democratic junior senator, has made running as a woman a central theme of her candidacy, and nearly two-thirds of the campaign’s donors were women, said the spokeswoman, Meredith Kelly.

Ms. Kelly did not disclose how many donors the campaign had, but she said that 92 percent of contributions were under $200.

Given her modest haul so far, Ms. Gillibrand will likely need to rely heavily upon the roughly $10 million in campaign funds she had left over after her Senate re-election bid last year. Only a few 2020 candidates had such a large cash stockpile to supplement their presidential fund-raising.

Despite that campaign war chest and Gillibrand’s high profile as a US Senator, she’s currently polling at 0.4% in the RCP aggregate. That’s below Marianne Williamson and Andrew Yang.

No doubt this will bring back memories of DNC intervention in the 2016 primaries, too, which were more clandestine and done on behalf of one candidate. At least for now, no one’s complaining that Perez has his thumb on the scale for any particular candidate with these rules. When they start squeezing candidates into analyst gigs on cable-TV channels, though, expect to hear some grumbling about the “establishment.”

Still, it’s tough to fault the DNC for imposing order on its own process. Most of these candidates have already been in the race for months, but even the most recent additions have had a few weeks to organize and raise their profiles. It’s not the DNC’s fault that three sitting governors can’t make the September debate threshold combined. (Jay Inslee doesn’t even show up on RCP’s radar.)  Perez and the DNC are giving plenty of notice for the new standards, and they’re also calculating a reasonable post-Labor Day start date for raising the threshold. They can’t hold pre-primary primaries to narrow the field, so they’re going on the only metrics available — polling and donor counts.

Regardless of whether one likes those metrics, now candidates know what they have to achieve to stay on the stage. If they can’t move those needles by September, they should really have already started looking for something else to do in 2020 anyway.