Employee's rights against employer who tries to break up union membership WA state employment law

Can an employer repeatedly reorganize to try to break the union and eliminate older workers?

My WA state employer recently reorganized and laid off 5 workers (4 union & 1 nonunion) in one job classification. Two jobs were created & filled by the junior union workers after the position were modified. The most senior employee, a shop steward, applied for another position for which s(he) qualified for, but was passed over. The last employee's skills did not line up with the new set of requirements and did not apply for any of the new positions.

The employer brought in a consultant who recommended the elimination of the positions outlined above. The employer was successful in breaking the union and eliminating two age 50+ workers.