LAS VEGAS – Nineteen Democratic nominees for president are traveling to Southern Nevada Saturday for a forum that will put them in direct conversation with workers from the country’s largest public employee labor union.

And a big endorsement is on the line.

The American Federation of State, County and Municipal Employees – the union hosting the event at UNLV – represents national support all the candidates covet.

"AFSCME [is] essentially laying down a marker here, saying this is an important state," said veteran political journalist Jon Ralston, editor of The Nevada Independent and a moderator at Saturday's forum in Las Vegas with HuffPost Washington Bureau Chief Amanda Terkel. "This is an important state for labor. [Nevada] is a place you need to come and state your views, and the fact that they chose Nevada for something like that is very, very significant both for the labor movement and the state.”

A crowded field seeks labor vote

Those seeking the Democratic nomination for president are in a crowded field, which has grown to 24 nominees. And others could still join the race.

There is still a long way to go until the general election on Nov. 3, 2020, when voters will determine who will hold the Oval Office for the next four years.

On Saturday, the candidates will take the stage, one at a time, to answer questions from moderators and AFSCME members – questions that will likely center on the nominees' plans to stand behind and fight for labor unions.

Their answers could shape how the union – a big player in past Nevada elections that represents 1.4 million members in communities across the country – picks a candidate come endorsement time.

So far in this election cycle, there's been one major union endorsement. In April, Joe Biden snagged the support of International Association of Firefighters.

In Nevada, the endorsements of the Culinary Union, the state's largest labor organization, and AFSCME are still up for grabs.

"AFSCME is a big, big deal for them to get," Ralston said. "Of course, it’s going to be a major suck-up parade."

Debate, 'Medicare for All' bound to surface

As it relates to possible impacts on union workers, "Medicare for All," one of the most contentious policy issues in the Democratic Party, could be a sticking point during Saturday's forum.

Bernie Sanders, the two-time Democratic presidential hopeful from Vermont, has championed the policy along the campaign trail. However, more moderate candidates are using the policy to fuel criticisms of poll-leading progressive nominees.

On night one of the Democratic presidential primary debate in Detroit, Michigan, former Maryland Rep. John Delaney, Montana Gov. Steve Bullock and former Colorado Gov. John Hickenlooper stood against getting rid of private health care insurance and replacing it entirely with a Medicare-for-all system.

In a quotable moment, Delaney criticized Warren, saying that Democrats want "real solutions" and "not impossible promises."

“I don’t understand why anybody goes to all the trouble of running for president of the United States just to talk about what we really can’t do and shouldn’t fight for,” she shot back at the former congressman. “I don't get it.”

Warren's line was met with applause from the debate audience.

AFSCME's 2020 Public Service Forum in Las Vegas will be the first time in this election cycle that candidates could face rebuttals to their debate performances.

The event will be live-streamed on HuffPost.com.

The participants (in alphabetical order):

Sen. Michael Bennet

Former Vice President Joe Biden

Sen. Cory Booker

Mayor Pete Buttigieg

Gov. Steve Bullock

Former HUD Secretary Julián Castro

Mayor Bill de Blasio

Former Rep. John Delaney

Rep. Tulsi Gabbard

Sen. Kamala Harris

Gov. Jay Inslee

Sen. Amy Klobuchar

Rep. Seth Moulton

Former Rep. Beto O’Rourke

Rep. Tim Ryan

Sen. Bernie Sanders

Business leader and philanthropist Tom Steyer

Sen. Elizabeth Warren

Author Marianne Williamson.

Contributing: The Associated Press