The Democratic National Committee released new, more difficult requirements candidates must meet to qualify for the fifth round of debates to be held in November, setting up the possibility that several additional candidates may miss the stage.

As in previous debate rounds, the requirements announced Monday include specific donor thresholds and polling numbers. But the new rules raise those bars.

To qualify for the November debate, candidates must receive individual donations from at least 165,000 people, consisting of at least 600 unique donors in at least 20 states.This is up from the previous requirement of 130,000 donors and at least 400 donors in 20 states, which were the marks set for the September and October debates.

The polling threshold has also been bumped up but includes another category of polls that could be used to qualify. Candidates must stand at 3% or higher in at least four approved national or early state polls. Or they can reach 5% or higher in two early state polls. Early states include Iowa, New Hampshire, South Carolina and Nevada.

Previously, candidates needed 2% or higher in qualifying polls for the September and October debates.

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The DNC has listed 15 pollsters it will accept as qualifying. The polls must be conducted between Sept. 13 and a week before the date of the November debate, which is yet to be announced.

The first and second rounds of debates saw a stage with 20 candidates each who had to be split into two nights. In September, tightened requirements left only 10 qualifying, and 11 have qualified for October's debate so far. Candidates have until Oct. 1 to qualify for the next round.

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Some Democrats have publicly criticized the DNC's requirements, calling them arbitrary. Hawaii Rep. Tulsi Gabbard, who did not qualify for the September debate, has bashed the DNC in the past for the number of polls it recognizes, saying that other reputable pollsters are left out.

"The Democratic National Committee has the responsibility to facilitate more conversations between the future leaders of this country, not less," Gabbard's campaign wrote in a statement last month.

Businessman and 2020 candidate Andrew Yang said on Monday that the DNC raised the bar this time in a "fair and transparent manner."