The ACA hurt every existing insurance plan out there. Ups wanted all employees Union and non-union under one insurance policy. This would have hurt plans that were currently being administered by the teamsters. All those plans would have suffered greatly without the money that Ups gives them. The union had to take on health insurance to save health insurance for every other non Ups Teamster out there.
Maybe you haven't noticed that it costs a few more dollars at the optometrist, the dentist, and the doctor. Again Where's the Democrat politicians that helped the unions as a whole?