NORTH CHARLESTON, S.C. (AP) — Nearly 3,000 production workers at Boeing's South Carolina plant are deciding whether they want to unionize, writing the next chapter in efforts to organize labor in large manufacturing plants across the South.

The first round of voting began early Wednesday. A second round was set for Wednesday afternoon to accommodate all employees.

If successful, the balloting on whether employees should join the International Association of Machinists and Aerospace Workers would send a significant message to politicians in the region and Washington that workers here want the same protections and benefits as those in other areas. And, to leaders trying to recruit businesses by promoting their states' lack of union presence, it'd make their jobs more difficult.

But this most recent test of Southern acceptance of collective bargaining movements is an uphill battle for the union and its backers. The global aviation giant, which came to South Carolina in part because of the state's minuscule union presence, did so with the aid of millions of dollars in state assistance made possible by officials who spoke out frequently and glowingly with anti-union messages.

"It is an economic development tool," Gov. Nikki Haley, now President Donald Trump's ambassador to the United Nations, said in a 2012 address of how she sold companies on coming to the state. "We'll make the unions understand full well that they are not needed, not wanted and not welcome in the state of South Carolina."

At least that part of the tactic has worked. Only about 52,000 South Carolina workers have union representation, according to the U.S. Bureau of Labor Statistics' 2016 figures. Other major manufacturers in the state, including BMW and Michelin, aren't unionized or haven't experienced major campaigns to do so. The Machinists initially petitioned for a vote at Boeing in 2015 but withdrew the request because of what the union called a toxic atmosphere and political interference.

Another facet of union opposition in this heavily Republican state is political, given the longstanding relationship between organized labor and Democratic politics. Any lenience toward unions could be seen as giving Democrats a toehold here.

Southern states for decades have recruited manufacturers by promising freedom from the influences of labor unions, which except for some textile mills have been historically rejected by workers as collective action culturally foreign to a South built around family farms, said Jeffrey Hirsch, a law professor who specializes in labor relations at the University of North Carolina at Chapel Hill.

A successful union vote at Boeing would have a greater regional impact than Volkswagen workers' efforts to unionize in Chattanooga, Tennessee. Anti-union advocates cited VW as an aberration since representatives of one of its key unions in Germany hold seats on the company's board of directors, Hirsch said.

"Boeing is very, very different," Hirsch said. "No one will ever accuse Boeing of being pro-union."

A "yes" vote could inspire others in the region to consider unions, said Daniel Cornfield, sociology professor and labor expert at Vanderbilt University.

What strikes Cornfield about the Boeing case is the company's silence over consequences if its workers unionize.

"The company has not been threatening to relocate its operations in the event of a unionization," he said. "It is often the case that companies try to relocate outside of the United States to find cheaper labor and avoid U.S. unions altogether."

Boeing may have abstained from those threats because of its huge South Carolina plant investment and billions of dollars in federal defense contracts the company does not want to risk.

Cornfield said Trump's pressure on business to keep jobs in the U.S. could be "defanging large corporations in their efforts to resist unionization ... giving workers a leg up and unions a leg up in the campaign period."

The union vote also comes after Trump blasted Boeing for the cost of building a new Air Force One.

"Costs are out of control," Trump tweeted in early December. "Cancel order!"

Boeing CEO Dennis Muilenburg met with Trump two weeks later.

Catherine Templeton, South Carolina's former labor director and successful anti-union lawyer, is no stranger to this fight. When Haley picked Templeton to lead South Carolina's labor department, the governor played up Templeton's union-fighting background and saying she needed her help to "fight the unions" at Boeing.

"They cannot legally deliver higher wages, better benefits or a different working environment. Even if they are promising it, they certainly can't deliver it," Templeton said.

On Monday, several hundred Boeing employees gathered in a hotel ballroom just a mile from the plant, hearing from activists and members of other unions urging them to vote "yes."

"Suppressing working people is the old way of doing business in South Carolina," Machinists organizer Mike Evans said, to cheers. "It's not going to be this way anymore."