Now that the field for candidates vying for the Democratic presidential nomination in 2020 has swelled to 24, there is a possibility that the first debate in Miami at the end of June could include a tech entrepreneur and self-help guru, but not a two-term senator or three-term congressman.

The reason lies in the Democratic National Committee’s debate threshold rules, which require a candidate to either have 65,000 donors from 20 states or register 1 percent in at least three polls. The rules have drawn ire from some in the Democratic Party, but on Wednesday, DNC Chair Tom Perez defended the committee’s rules.

Perez said that after the tumultuous, and sometimes caustic, primary between Sen. Bernie Sanders and former Secretary of State Hillary Clinton in 2016, the party wanted to place a stronger emphasis on grassroots fundraising and organizing.

“We did it because I firmly believe if you want to win the presidency in this year, you have to build a grassroots fundraising operation and connect with the grassroots,” Perez said during an interview with Boston Public Radio on Wednesday.

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The 2020 presidential election has already proven to be historic. This pool of 24 Democratic candidates is already the largest for any political party since our current system of primaries and caucuses began in 1972. While some, like Perez, are excited by the big field, others are concerned that the inevitable fighting between the candidates will diminish the Democrats' ability to defeat President Donald Trump in the general election.

“Trump can run his general election campaign while Democrats compete with one another,” Washington Post journalist Dan Balz wrote in a May 18 opinion article. “ As Democrats speak with many voices, Trump and the Republicans will try to define the party on the basis of the most extreme proposals or outlandish controversies.”

Perez, however, says that it’s a sign of the party’s vitality. He defended the criteria to enter the first debates, saying that it ensures that as many voices, ideas and policies can participate in the 2020 primaries, and “have a chance to articulate their vision.”

“I think the grassroots fundraising threshold has catalyzed incredible activity. ... The number of people who are engaged for the first time as a result of this criteria is remarkable, and I think that’s exactly what we want to do,” Perez said. “I’ve had the privilege of working pretty closely with probably three-quarters of them [and] I think it’s a first class challenge to have.”

The large number of candidates who have already qualified for the first two debates, however, does appear to have made an impression on the DNC. On Wednesday, the committee announced that for candidates to qualify for the third debate in September, they will need to receive 130,000 donations from donors in at least 20 states, and poll at 2 percent or higher in at least four national polls or surveys.

Recalling the perception in 2016 that the Republican Party had a two-tiered debate system, in which more popular candidates debated on one night while lesser-known ones debated the second, Perez said that June’s debates will feature front-runners and lesser-known candidates sharing the stage to “maximize eyeballs.”

“We don’t want people to perceive that there’s only one night to watch,” Perez said. “We will have a situation where there are a critical mass of folks polling in the top eight ... and then a critical mass of those who are not polling in the top eight will also be on each night. That sort of mix ... is going to give a really exciting dynamic.”

So far, the candidates who have qualified for the first two debates in June are: former Vice President Joe Biden, Sen. Bernie Sanders, Sen. Kamala Harris, former Rep. Beto O’Rourke, Sen. Elizabeth Warren, Sen. Cory Booker, Sen. Amy Klobuchar, Mayor Pete Buttigieg, former Secretary of Housing and Urban Development Julian Castro, Sen. Kirsten Gillibrand, Gov. Jay Inslee, Gov. John Hickenlooper, entrepreneur Andrew Yang, former Rep. John Delaney, Rep. Tulsi Gabbard, Gov. Steve Bullock, Rep. Tim Ryan, Rep. Eric Swalwell, Mayor Bill de Blasio, and self-help author Marianne Williamson.