Discrimination against employees that are union

I currently work for a union shop that is owned by a major corporation. Many of these shops that are currently owned by the same corporation don’t have a bargaining unit contract. We have one shop that was tiring to organized and were assembled to a meeting and were told that all of us union members will be fired at the end of our contract and that he will do everything in his power to make sure that anybody that work for that union shop will never work for this corporation ever again. Normally none of us would worry much about what was said by this corporate officer but our understanding is that this guy will be promoted to western region resident and will have the means to execute this threat to black ball all of us union members. Can the corporation be sued for his actions? What recourse can the union members take?

thanks