Portside

The United Auto Workers union has waged a long and mostly futile campaign to organize factories in the South, where much of the nation’s auto production has shifted. Now the union sees a breakthrough in sight.

On Tuesday, the U.A.W. said a petition for a union election had been filed by employees at a Nissan plant in Mississippi with more than 6,000 workers. They asked for a vote within a month.

A victory at the plant, which the U.A.W. has been working hard to unionize since 2012, would be a major prize in a traditionally hostile region. The effort comes almost three and a half years after the union’s last high-profile election at a so-called foreign transplant facility, a Volkswagen plant in Chattanooga, Tenn., ended in a narrow defeat.

Union officials announced the organizing milestone at a news conference near the Nissan plant in Canton, Miss. In a statement, the U.A.W. cited “a pattern of labor abuses by Nissan against its predominantly African-American work force in Mississippi” and said the plant was “one of only three Nissan facilities in the world” that lack a union.

Nissan said in a statement that it offered “stable, safe jobs with some of the best wages and benefits in Mississippi” and that it did not believe that U.A.W. representation “is in the best interest of Nissan Canton and its workers.”

The plant is a key component in Nissan’s growth in the United States market. Stretching nearly a mile long, the factory is larger than most assembly plants, and it makes several models, including the Murano S.U.V. and the Titan pickup truck.

Employees at the plant complain that the company relies too heavily on contract workers, whose hourly wages are lower but who some say get cushier assignments as a way to reduce turnover. Workers also cite safety concerns — the company has been fined by the Occupational Safety and Health Administration in a few instances over the last five years, including once when a worker’s hand was caught in a conveyor roller.

To petition for an election with the National Labor Relations Board, unions must show support from at least 30 percent of eligible rank-and-file workers, and they rarely do so with less than 50 percent. (The U.A.W. estimates that about 4,000 workers are eligible to vote in Canton.) But the challenge facing the union this time could be far greater than during the Tennessee campaign.

“Nissan has been a hard nut to crack for the U.A.W.,” said Kristin Dziczek, a labor expert at the Center for Automotive Research. “Mississippi is very challenging.”

The union lost its first Nissan unionization vote at an assembly plant in Smyrna, Tenn., in 1989. It tried again there in 2001 and lost by a big margin.

Unlike Volkswagen, Nissan has actively opposed unionization; it has, for example, shown videos and held meetings with workers in which it makes its case.

The union, for its part, has filed numerous charges with the National Labor Relations Board accusing Nissan of violating labor rights. The union asserted that a Nissan security guard had prevented workers from distributing union material outside a plant entrance and that the company had threatened to close the plant if workers unionized.

Chip Wells, a longtime worker at the plant, said he had been repeatedly harassed by a supervisor for supporting the union — for example, the supervisor once sent him to the human resources office and cited him for tardiness when he was not back by the time his break ended. “She was pushing my buttons,” he said. “Or trying to push my buttons to get me to go.”

A Nissan spokeswoman, Parul Bajaj, said that Mr. Wells’s allegations were unsubstantiated and that the union’s charges of intimidation were simply an organizing tactic. Ms. Bajaj added, “Nissan’s Canton plant has a safety record that is significantly better than the national average for automotive plants.”

In Canton, the union has some advantages that it might have lacked in Tennessee, where the political class tended to be relentlessly opposed to the union at Volkswagen even as the company stood down.

While Mississippi’s political leadership is no more hospitable to unions — Gov. Phil Bryant signed legislation in 2014 that restricted union activity — the racial dynamic at the Canton plant, where well over half the workers are African-American, could make attacks by the state’s largely white conservative leadership less effective.

The union appears to have calibrated its strategy accordingly, missing few opportunities to highlight the issue of race.

“Nissan spends hundreds of millions of dollars a year marketing itself as a socially responsible carmaker, even going so far as to brag about its appeal to African-American car buyers,” Rahmeel Nash, a longtime worker at the plant, said in the union’s statement. “But behind the scenes, the company is violating the labor rights of African-American workers who make those cars.”

During its Mississippi campaign, the union has forged strong alliances with civil rights groups and clergy, helping to organize a high-profile rally in the area in March featuring the actor Danny Glover, Senator Bernie Sanders of Vermont and Cornell William Brooks, then the president of the N.A.A.C.P.

“Some of the issues I gather in the Nissan plant are similar to the issues in Chattanooga and elsewhere,” said Daniel Cornfield, a labor expert at Vanderbilt University. “But in the case of Mississippi, they are being framed in terms of respect and disrespect for workers, and linking that to a civil rights orientation.”

Duane O’Neill, the president of the Greater Jackson Chamber Partnership, a business group that opposes unionization, said, “Anytime you’re discussing issues like this in the context of race, it becomes a little more sensitive.” But he added that his group had worked closely with Nissan in Mississippi and that “I just don’t see that as being an issue.”

Mr. O’Neill emphasized that a unionization decision was up to the workers. But he expressed concern that it could discourage future employers from relocating to central Mississippi and jeopardize economic growth.

Since its setback at Volkswagen, the U.A.W. has not been bereft of momentum. Volkswagen soon allowed its Chattanooga workers to join voluntary unions that did not collect dues, and the union later succeeded in organizing a small group of skilled-trades workers in the plant. The union has also enjoyed some recent organizing successes at auto-parts suppliers across the South, including at least one since 2014.

Nissan, for its part, is riding some momentum of its own. It has been growing in the United States market, even as sales in the overall industry have tapered off after two record years. In the first six months of this year, Nissan sales — including its Infiniti luxury division — have increased 2.7 percent, compared with a 2.1-percent decline for the industry as a whole.

Sales of Nissan’s Rogue compact S.U.V. are up more than 30 percent this year, and the Canton-made Titan has more than quadrupled its sales from a year ago.

The company said that wages at the Canton plant were “significantly above the average central Mississippi production wage of $16.70 per hour” and that workers received consistent bonuses, health benefits and employer contributions to a 401(k) plan.

The three Detroit automakers pay veteran union workers a top hourly wage approaching $30, and the hourly pay for new entry-level employees approaches $20. Foreign competitors like Nissan operating in the United States do not routinely disclose pay scales. But the Center for Automotive Research estimates that labor costs at nonunion plants in the South can be 15 to 25 percent lower than at those operated by General Motors, Ford Motor and Fiat Chrysler.

The Nissan workers who filed for the election asked that it take place on July 31 and Aug. 1, a rapid but not unheard-of turnaround, said Wilma Liebman, a former N.L.R.B. chairwoman.

In doing so, the workers and the union appear to have calculated that the window for their opportunity to organize the Nissan facility may be closing, with President Trump having recently made two Republican nominations to the labor board. A board more hostile to organizing could make it easier for the company to overturn a union victory, or be more likely to reject union appeals after the fact.

“I think N.L.R.B. changes have to be playing a role here,” Ms. Dziczek said.