The knock-down, drag-out fight in Wisconsin isn’t about how much public employees will pay toward their pensions and health-insurance premiums. As union members have loudly insisted, they are willing to make concessions this year on those items, so long as Gov. Scott Walker will leave their collective-bargaining rights alone. The reason both sides have dug in is that they understand the long-term stakes: By reforming collective bargaining, Walker stands not only to achieve cost savings this year, but also to reassert the state’s control over runaway employment costs for years to come — and to allow local governments to do …