Workers were trying to unionize, and they wore buttons showcasing their cause. Supervisors demanded the buttons be removed, and they disciplined a half-dozen employees who didn't listen. The workers filed a complaint with the federal government, saying their rights were being violated. Dissidents also claimed later that three ringleaders of the organizing effort were let go because of their activism. Employees trying to unionize often face resistance -- or retribution -- from bosses. But the employees in this instance weren't working at some factory or warehouse. They're actually employed by a union. They're organizers and clerical staff for the fast-growing...