The United Auto Workers (UAW) suffered a significant setback on Friday when workers at a Mercedes-Benz plant in Alabama voted against joining the union. This decision marks the first major loss for UAW organizers following a series of victories, including substantial raises for Detroit workers and the union’s expansion to a VW factory in Chattanooga last month.

The vote, overseen by the U.S. National Labor Relations Board, saw 56% of the workers at the plant in Vance, Alabama, and a nearby battery facility vote against joining the UAW. The result still needs to be certified, but it clearly indicates a resistance to unionization among the workers.

The UAW had hoped to continue its winning streak, which included a lucrative new contract at six Daimler Truck facilities across the South. However, this loss has left the union’s next steps unclear. The UAW has been in the midst of a $40 million campaign targeting other automakers, including Toyota and Tesla.

The union’s loss at Mercedes complicates its efforts to expand its influence, especially in the South. The UAW will need to redouble its efforts to win over workers in a region that has previously been inhospitable to unions. Widening its reach beyond the Detroit automakers is critical for the UAW to maintain its influence within the industry.

The company made its feelings clear in the run-up to the vote. Signs urging workers to vote “no” were hung around the Alabama plant, and the company hired anti-union firms to speak with workers about the potential risks of joining the UAW. Despite these challenges, the UAW remains committed to its mission and will continue its efforts to organize workers in the automotive industry.