Despite entreaties from the candidates running for president, the Democratic National Committee announced new higher thresholds needed to qualify for the debate stage in Iowa in January.

The new benchmarks, announced by the DNC on Friday, require candidates to have 225,000 unique donors, as well as show 5 percent or more support in at least four national or single-state polls in early voting states Iowa, New Hampshire, South Carolina and Nevada. Candidates could also qualify by reaching 7 percent or more support in two single-state polls in Iowa, New Hampshire, South Carolina and Nevada.

For Thursday's sixth Democratic debate in Los Angeles, which featured the smallest field of candidates to make the stage to date, candidates needed to have 200,000 donors to make the stage, and hit 4 percent in four qualifying national or state polls, or 6 percent in two polls of the early states: Iowa, New Hampshire, Nevada and South Carolina.

A review of polling data by NBC News shows five candidates have qualified under the polling criteria for Jan. 14 debate at Drake University in Des Moines, which is being hosted by CNN and the Des Moines Register — former Vice President Joe Biden, South Bend, Indiana, Mayor Pete Buttigieg and Sens. Amy Klobuchar of Minnesota, Bernie Sanders of Vermont and Elizabeth Warren of Massachusetts.

Former New York City Mayor Mike Bloomberg would qualify under the polling criteria, but is not soliciting donations, so will presumably not meet the donor threshold.

Two candidates in the debate Thursday have not yet qualified — billionaire activist Tom Steyer and entrepreneur Andrew Yang.

Among those left off the stage this week were two candidates of color, Sen. Cory Booker of New Jersey and former Housing and Urban Development Secretary Julián Castro.

Booker told MSNBC's Andrea Mitchell on Friday that the DNC's reliance on polls is misplaced.

"The polls have never been predictive. In fact, the front-runner at this point in every one of our presidential elections, the Democratic Party of our lifetime, the front-runner has never gone onto the White House. So we know this election is wide open," Booker said. "I don't understand what the DNC's doing but I'm not here to argue with the refs."

Led by Booker, nine candidates called on the DNC last week to ease the qualification thresholds to keep the debate stage diverse.

“The escalating thresholds over the past few months have unnecessarily and artificially narrowed what started as the strongest and most diverse Democratic field in history before voters have had a chance to be heard,” the candidates wrote in an open letter to the DNC.

“As a result, candidates who have proven both their viability and their commitment to the Democratic Party are being prematurely cut out of the nominating contest before many voters have even tuned in — much less made their decision about whom to support,” said the letter, which was signed by the seven candidates who made the debate stage in L.A., as well as Booker and Castro.

The DNC said it would proceed as planned.

“The DNC has led a fair and transparent process and even told campaigns almost a year ago that the qualification criteria would go up later in the year — not one campaign objected,” DNC spokesperson Xochitl Hinojosa said Saturday.

“The DNC will not change the threshold for any one candidate and will not revert back to two consecutive nights with more than a dozen candidates."

The first Democratic debate in June featured 20 candidates divvied up over two nights. The threshold to make the stage then was to hit 1 percent in three qualifying polls or provide evidence of at least 65,000 donors.