After struggling a setback at two Mercedes-Benz crops in Alabama on Friday, the United Vehicle Employees union’s efforts to arrange different auto factories within the South are more likely to gradual and will battle to make headway.

About 56 % of the Mercedes employees who voted rejected the U.A.W. in an election after the union chalked up two main wins this 12 months. In April, employees at a Volkswagen plant in Tennessee voted to hitch the union, the primary giant nonunion auto plant within the South to take action. Weeks later, the union negotiated a brand new contract bringing vital pay and profit enhancements for its members at a number of North Carolina factories owned by Daimler Truck.

“Dropping at Mercedes is just not dying for the union,” mentioned Arthur Wheaton, director of labor research at Cornell College Faculty of Industrial and Labor Relations. “It simply means they’ll have much less confidence going to the subsequent plant. The U.A.W. is in it for the long term. I don’t assume they’re going to cease simply because they misplaced right here.”

Since its founding in 1935, the U.A.W. has nearly completely represented employees employed by the three Michigan-based automakers: Common Motors, Ford Motor, and Chrysler, now a part of Stellantis. And it has lengthy struggled to make headway at crops owned by international producers, particularly in Southern states the place anti-union sentiment runs deep.

Employees on the Volkswagen plant had voted towards being represented by the U.A.W. twice by slender margins earlier than the latest union win there. An effort a decade in the past to arrange one of many Mercedes crops didn’t construct sufficient assist for an election.

Harley Shaiken, a professor emeritus on the College of California, Berkeley, famous that broad union organizing efforts seldom proceeded easily. Within the Thirties, the U.A.W. gained recognition at G.M. and Chrysler however struggled at Ford, which continued using nonunion employees for a number of years.

“I’ve little doubt they may proceed organizing and finally attempt for an additional vote,” he mentioned.

In its previous efforts within the South, the union was hampered by a unfavorable picture, which can have additionally performed an element within the U.A.W.’s loss at Mercedes. For years, the three Michigan automakers have been chopping jobs and shutting crops, partly due to inflexible and expensive labor contracts. The union was additionally damage by corruption instances that put a number of former senior officers, together with two former U.A.W. presidents, behind bars.

Enterprise leaders in Alabama ran a marketing campaign towards the U.A.W. that was primarily based partly on the rivalry that the union was liable for the decline of Detroit. In a January opinion essay printed in The Alabama Every day Information, the chief government of the Enterprise Council of Alabama, Helena Duncan, mentioned the state would undergo the identical destiny if employees voted for the union.

“A lot of the decay that exists within the ‘Motor Metropolis’ at this time outcomes from untenable calls for that the U.A.W. positioned on its vehicle producers, an unwise transfer that despatched untold numbers of jobs to right-to-work states like ours and crippled a as soon as nice metropolis,” Ms. Duncan wrote.

A 12 months in the past, the union elected a brand new president, Shawn Fain, who was untouched by the corruption scandals and vowed to take a extra aggressive strategy in contract talks. Then final fall, the union got here away with substantial pay and profit good points in negotiations with the Detroit automakers, after focused strikes over some 40 days. A whole bunch of Southern autoworkers started reaching out, asking for assist organizing their nonunion crops. The U.A.W. responded by asserting that it could spend $40 million on organizing drives over the subsequent two years.

“I’m not scared in any respect,” Mr. Fain mentioned Friday in Alabama after the union misplaced the Mercedes vote. “I consider employees need unions, I consider they need justice, and we’re going to proceed doing what we will do.”

Mercedes in an announcement emphasised its direct relationship with employees and mentioned it regarded ahead to creating positive the corporate was “not solely their employer of selection, however a spot they might advocate to family and friends.”

The union has signaled that it expects to focus its organizing efforts on one other Alabama plant — a Hyundai manufacturing unit in Montgomery. However organizing that plant will most likely be even tougher than the marketing campaign on the Mercedes factories, mentioned Erik Gordon, a College of Michigan enterprise professor who follows the auto business.

The U.A.W. had allies at Volkswagen and Mercedes. Unions are highly effective gamers in Germany, the place these two firms are primarily based. Beneath German regulation, employee representatives should occupy half the seats on an organization’s supervisory board, the equal of an American board of administrators.

Volkswagen and Mercedes each have teams known as works councils by which managers and workers focus on and negotiate office points and manufacturing plans. In its drive on the Volkswagen plant in Chattanooga, the U.A.W. had the assist of the corporate’s works council and IG Metall, the highly effective union that represents all German automotive employees.

The U.A.W. gained’t have that sort of assist at Hyundai’s Montgomery plant, Mr. Gordon mentioned. “Basically, Korean automotive firms have extra adversarial relationships with unions than do the German producers,” he mentioned. “Korean firms are much less used to sitting collectively in a convention room with unions.”

Final 12 months, weeks after the U.A.W. gained pay and profit will increase from the three Michigan-based automakers, Hyundai introduced that it could improve its employees’ pay sharply over the subsequent 4 years — a transfer extensively seen as an try to dampen employees’ curiosity in becoming a member of the U.A.W.

“The choice to be represented by a union is as much as our group members,” Hyundai mentioned in an announcement.

The Montgomery plant makes two widespread sport utility automobiles — the Tucson and Santa Fe — and employs about 4,000 employees. An earlier U.A.W. drive to arrange the plant in 2016 petered out with out coming to a vote.

Final fall, the union mentioned it deliberate to focus on crops owned by 10 foreign-owned automakers — Toyota, Honda, Hyundai, Nissan, BMW, Mercedes, Subaru, Volkswagen, Mazda and Volvo — and others owned by Tesla, which relies in Texas, and two smaller electrical car start-ups, Lucid and Rivian, each primarily based in California.

The U.S. crops owned by these international and U.S. firms make use of practically 150,000 employees in 13 states, the union mentioned.

In Alabama, nevertheless, the U.A.W. confronted maybe a extra hostile setting than wherever else. Whereas it was campaigning at Mercedes, Gov. Kay Ivey spoke out towards the union and headed a bunch of six Southern governors, all Republicans, who issued a letter suggesting unionizing might trigger automakers to maneuver jobs out of their states. One senior Alabama politician described the U.A.W. as “leeches.”

Mercedes introduced in Nick Saban, the massively widespread former soccer coach on the College of Alabama, to speak to employees in an effort to influence them to vote towards the U.A.W.

Unions are historically seen as a Northern establishment and are sometimes linked with the civil rights motion, which alienates many individuals in Alabama, Mr. Gordon mentioned. “It’s a really powerful place for the U.A.W.,” he mentioned.

That antipathy might additionally make it onerous for the U.A.W. to barter contracts guaranteeing its members raises and different good points even when it wins unionizing votes. Lawmakers who oppose unions might put stress on employers to not make massive concessions in negotiations.

Mr. Fain and the U.A.W. have argued that unions are one of the best ways for employees to demand increased wages when automakers are having fun with sturdy gross sales and earnings in North America.

Public assist of unions is stronger than it has been in years, together with within the South. This 12 months, 600 employees at an electrical bus manufacturing unit in Alabama voted to hitch the Communications Employees of America union. Every week in the past, they negotiated a brand new contract delivering pay raises and enhanced advantages.

The U.A.W. and different unions even have loved the assist of President Biden, who final fall joined hanging autoworkers on a picket line in Michigan. The union endorsed Mr. Biden on this 12 months’s election.

However that shut affiliation with the president may additionally damage the U.A.W. with conservative employees in a Southern state preferring Mr. Biden’s opponent — former President Donald J. Trump. Mr. Fain and Mr. Trump have usually criticized one another, however polls have proven that a sizable minority of union households support the former president.