LOS ANGELES — The next Democratic presidential debate will go on as scheduled Thursday, after negotiators on Tuesday reached agreement in a labor dispute that had threatened to upend the event while highlighting the influence that organized labor wields with the leading Democratic presidential candidates.
The debate, which will be held at Loyola Marymount University, had been in question since last week after the seven participating Democrats each said that they would not cross a picket line, if there was one.
The dispute, between a cafeteria workers union and a food services company at Loyola Marymount, involved only about 150 workers and had drawn little notice over nine months. Yet in the heated political atmosphere surrounding the 2020 Democratic presidential contest, the impasse attracted outsized attention this month as the sixth primary debate approached.
The Democratic National Committee chairman, Tom Perez, spent the weekend on the phone with the union, Unite Here Local 11; their employer, the food services provider Sodexo; and other local officials. The two sides resumed negotiations Monday and announced a tentative agreement Tuesday morning.
“I was proud to help bring all stakeholders to the table, including Unite Here Local 11, Sodexo and Loyola Marymount University, to reach a deal that meets their needs and supports workers,” Mr. Perez said Tuesday.
The D.N.C. informed the presidential campaigns of the resolution shortly before 9 a.m. Tuesday. Mr. Perez is scheduled to appear at a news conference with union officials later in the day in Los Angeles.
While few had expected the debate to be canceled or moved, the episode provided the latest evidence of the importance of labor support to the leading Democratic candidates.
Their solidarity with the local union here follows a year in which Democratic candidates have made a show of proclaiming their support for organized labor — joining autoworkers demonstrating in Michigan and supporting strikes by public-school teachers — as they court one of the party’s most important constituencies.
“I’ve never seen an election where the candidates are walking picket lines, consistently talking about federal labor law, and being seen with union members as much as they can,” said Peter Dreier, a professor of politics at Occidental College. “Over the last decade or so labor unions have been making a comeback with much more visibility, more activism. Even though the unions haven’t gained many more members, they’ve definitely won a lot more support.”
The troubles began last Thursday when Sodexo, the company that has the contract to operate dining halls on the Loyola Marymount campus, put a temporary halt to contract negotiations with Unite Here, which represents the cafeteria workers. According to union officials, Sodexo said it would restart talks in January after the holiday season.
But that would have deprived workers of using the debate as leverage. So by Friday afternoon Unite Here Local 11, which is affiliated with the powerful Culinary Workers union that represents casino employees in Las Vegas, had extracted statements from all seven candidates saying they would not cross a picket line to debate at Loyola Marymount. Senators Elizabeth Warren and Bernie Sanders were the first candidates to publicly pledge solidarity with the cafeteria workers.
The move worked. A spokesman for Sodexo, Enrico Dinges, confirmed Tuesday morning that the two sides had reached a tentative agreement. The deal was announced while Mr. Perez was aboard a flight to Los Angeles.
The episode demonstrated the unique grip labor unions hold on California politics. In recent years the state’s labor unions have called strikes that have shut down public schools, hospitals and parts of Hollywood. Lawmakers in 2016 approved a statewide $15 minimum wage and, earlier this year, stringent laws declaring that contract workers such as Uber drivers should be classified as employees. The agency that oversees its public employee retirement program, known as CALPERS, is the nation’s largest public pension fund.
Given the influence unions wield in the state, showing solidarity with workers is important for any Democrat who hopes to win California’s delegate-rich primary on Super Tuesday in March.
Thursday’s debate, in fact, is only taking place at Loyola Marymount because the Democrats’ first choice as host, the University of California, Los Angeles, is enmeshed in a labor dispute of its own. The powerful AFSCME union has been battling the University of California system for three years over outsourcing on campuses and medical centers. Less than two weeks after announcing U.C.L.A. as the debate host in late October, party officials announced they were searching for a new location in the area and eventually relocated to Loyola Marymount, about 15 minutes away.
The debate will take place against the backdrop of a historic vote in the House, expected Wednesday, on whether to impeach President Trump. And it follows days of anxiety among Democrats about the dwindling number of participants on the stage. Of the seven candidates taking part— the smallest number yet for a debate — just one, Andrew Yang, will be a person of color. The leading black and Latino candidates failed to qualify, leading to concern that the debate field won’t be representative of the electorate that will choose a nominee.
The gathering will also reflect a new order in the party’s nominating contest. Mayor Pete Buttigieg of South Bend, Ind., after charging to a lead in Iowa polls, has found himself under attack from Mr. Sanders and Ms. Warren. Mr. Sanders has also seen his stock rise in recent weeks as Ms. Warren has lost ground. Center stage will be occupied, as it has throughout the fall, by former Vice President Joseph R. Biden Jr., who remains the leader in national polling.
So far this year, labor unions have largely stayed on the sidelines, waiting to see how the Democratic field shakes out. Only a few endorsements have been handed out as unions try to push candidates closer to their preferred positions, leading to a prolonged courtship throughout the year by the leading primary contenders.
Mr. Dreier, the Occidental professor, said he has not seen sentiments this supportive of labor unions from the Democratic field in decades, and on Monday called Unite Here’s threat a “shot across the bow” for both Loyola Marymount and other universities that contract with Sodexo.
“They’re using this as a test of their strength,” Mr. Dreier said of the union. “This is a big coup for national attention.”
The union had been in negotiations with Sodexo since March and had occasionally set up picket lines at the school. The D.N.C. first became aware of the dispute on Friday when the union asked campaigns to pledge not to cross a picket line, officials said.
Ada Briceño, a co-president of Local 11, called Sodexo’s initial decision to postpone negotiations until January “a slap in the face.”
“We felt it was crucial to alert the candidates that this was a problem for us,” she added.
At least two of the candidates planning to debate are already in California. Mr. Sanders attended a rally Monday night in the Coachella Valley east of Los Angeles and Mr. Buttigieg of South Bend, Ind., attended fund-raisers in Northern California on Monday and had more planned for the Los Angeles area on Tuesday. The former Housing secretary Julián Castro, who did not qualify for the debate, is also holding events in the Los Angeles area.
If the debate had been canceled or moved to another location, it would have been a significant blow to Loyola Marymount, which operates largely in the shadows of larger Los Angeles campuses such as the University of Southern California and U.C.L.A. University officials had been silent since Friday, when they released a statement urging Sodexo to meet with Local 11 to “advance negotiations and solutions.”