TUSCALOOSA, Ala. (AP) — A decisive vote against the United Auto Workers at two Mercedes factories in Alabama sidetracked the union’s grand plan to sign up workers at nonunion plants mainly in the South. But President Shawn Fain said the UAW will return to Mercedes and will press on with efforts to organize about 150,000 workers at more than a dozen auto factories across the nation. Employees at Mercedes plants near Tuscaloosa voted 56% against the union. The Friday vote count handed the UAW a serious setback a month after the union scored a breakthrough victory at Volkswagen’s 4,300-worker assembly factory in Chattanooga, Tennessee.