In the biggest strike at U.S. oil refineries in 35 years, Tesoro Corp. has been hit the hardest, with workers walking out of three of its plants across the western U.S. That’s not just bad luck. Tesoro, the biggest refiner in the western U.S. by capacity, won a reputation in the last round of negotiations three years ago for being an especially hard bargainer with local United Steelworkers members. That’s put a bullseye on the company during the current negotiations. Changes pushed by the company in 2012 to cut profit-sharing and pension benefits “severely impacted the employees,” said Dave Campbell, secretary-treasurer of the USW local that represents Tesoro’s Carson and Wilmington refineries in Southern California. “Everyone was very, very angry.” The United Steelworkers, a union representing employees at more than 200 U.S. refineries, terminals, pipelines and chemical plants, stopped work at nine sites Feb. 1. after negotiations […]