The UAW has failed so far to make inroads with foreign automakers in the South. The companies have fended off the union by offering competitive wages and benefits.
Other German automakers like BMW, which has a plant in Spartanburg, S.C., and Daimler, which builds Mercedes vehicles in Vance, Ala., have a corporate structure similar to Volkswagen's and could face some of the same internal labor pressures.
Alabama's Republican Gov. Robert Bentley recently said a union at the Mercedes plant would be counterproductive.
In Tennessee, labor disagreements with Nissan date back more than three decades. Labor groups upset that the company used non-union construction workers to build a Datsun truck plant disrupted a groundbreaking ceremony in 1981 featuring then-Gov. Lamar Alexander, who is now Tennessee's senior U.S. senator.
Alexander at the time apologized to Nissan officials. He claimed "99.9 percent" of Tennesseans welcomed the automaker to the state, adding: "I really don't understand why this minority is trying to run off a company that's bringing into Tennessee 2,200 jobs."
Since then, several efforts to organize the workforce at Nissan's plants in Smyrna and Canton, Miss., have fallen short.
Associated Press Auto Writer Tom Krisher in Detroit contributed to this story.
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