NEW YORK (Reuters) - A sitting U.S. governor and a congressman will be among the four candidates left off the stage when the Democratic Party holds its pivotal first debate in Miami later this month.

The Democratic National Committee announced on Thursday the list of 20 presidential candidates who qualified to participate in the debate.

The decision deals a blow to the candidates who will be omitted: Montana Governor Steve Bullock, U.S. Representative Seth Moulton of Massachusetts, former U.S. Senator Mike Gravel, and Wayne Messam, the mayor of Miramar, Florida.

The debates, held over two nights on June 26 and June 27, will offer a sprawling Democratic field its first close-up with Americans and allow candidates who have trailed in opinion polls the opportunity for a poll-boosting viral moment.

The 20 qualifying candidates will be randomly divided between the two nights in a way that ensures top-polling candidates will be spread evenly between both debates. The drawing is expected to take place on Friday in New York.

Candidates qualified for the debates by receiving at least 1% in three polls, or by receiving donations from 65,000 supporters, including at least 200 donors apiece in 20 states.

In most years, the list of candidates to participate in a presidential debate would not garner much attention. But the historically large field of 24 candidates forced the Democratic Party to establish rules to limit participation and make the debates less unwieldy - and forced a mad dash from bottom-tier candidates to meet the requirements.

Bullock has been the most vocal critic of the system. He was the final candidate to enter the race after formally launching his presidential campaign in May.

He waited until after Montana’s legislature completed its session. But that gave him less time to build support in the polls or raise money.

FILE PHOTO: Twenty four 2020 Democratic presidential candidates are seen in a combination from file photos (L-R top row): U.S. Senators Bernie Sanders, Kamala Harris, Elizabeth Warren, Cory Booker, Amy Klobuchar, Kirsten Gillibrand, Michael Bennet and former U.S. Senator Mike Gravel. (L-R middle row): Former Texas congressman Beto O'Rourke, U.S. Representatives Tulsi Gabbard, John Delaney, Eric Swalwell, Tim Ryan, Seth Moulton, former HUD Secretary Julian Castro and former U.S. Vice President Joe Biden. (L-R bottom row): Mayor Pete Buttigieg, Former Gov. John Hickenlooper, Gov. Jay Inslee, Andrew Yang, Marianne Williamson, Mayor Wayne Messam, Montana Gov. Steve Bullock and New York City Mayor Bill de Blasio. REUTERS/Files/File Photo/File Photo/File Photo

“I had a job to do, and if it ultimately ever came down to choosing between getting Medicare reauthorized, getting 100,000 Montanans healthcare versus getting in earlier just to try to bump up on yet another poll, I’d make that same choice time and time again,” Bullock said on MSNBC after the list was finalized.

The debate will be broadcast in prime time on NBC, MSNBC, and Telemundo and be streamed online for free on a variety of digital and social platforms.

Here are the participants:

Senator Michael Bennet of Colorado

Former Vice President Joe Biden

Senator Cory Booker of New Jersey

South Bend, Indiana, Mayor Pete Buttigieg

Former Housing Secretary Julián Castro

New York Mayor Bill de Blasio

Former Representative John Delaney of Maryland

Representative Tulsi Gabbard of Hawaii

Senator Kirsten Gillibrand of New York

Senator Kamala Harris of California

Former Governor John Hickenlooper of Colorado

Governor Jay Inslee of Washington

Senator Amy Klobuchar of Minnesota

Former Representative Beto O’Rourke of Texas

Representative Tim Ryan of Ohio

Senator Bernie Sanders of Vermont

Representative Eric Swalwell of California

Senator Elizabeth Warren of Massachusetts

Author Marianne Williamson

Entrepreneur Andrew Yang