CHATTANOOGA (AP) — Workers at a Volkswagen factory in Tennessee have voted against union representation, a devastating loss that derails the United Auto Workers union's effort to organize Southern factories.The 712-626 vote released late Friday stunned many labor experts who expected a UAW win because Volkswagen tacitly endorsed the union and even allowed organizers into the Chattanooga factory to make sales pitches.But the union faced stern opposition from Republican politicians who warned that a union win would chase away other automakers who might come to the region. Sen. Bob Corker of Tennessee was the most vocal opponent, saying that he was told that VW would not build a new SUV in Chattanooga if workers approved the union. That was later denied by a VW executive in Tennessee.The UAW for decades has tried without success to organize a foreign-owned plant in a region that's wary of organized labor.