Republican Gov. Scott Walker pushed a law through the Legislature two years ago that stripped most public workers of their union rights and required them to contribute about 6 percent of their earnings to their pensions and pay 12 percent of their health insurance costs. State and local governments typically covered most, if not all, of employees' retirement contributions and health insurance costs before Walker introduced the law.

The law didn't extend to public safety workers, however. Responding to municipalities' fears that tensions would rise between police and firefighters and other public workers, Republican lawmakers included language in the 2011-2013 state budget that blocked police and firefighter unions from having any say in the design of their health insurance. Local government officials across the state saw the language as a green light to rework their employees' health insurance plans unilaterally.

The Milwaukee Police Association, which represents rank-and-file officers in that city, filed a lawsuit in September 2011 alleging that the budget language still allows for negotiations on officers' out-of-pocket costs, such as deductibles and co-payments. Milwaukee County Circuit Judge Dominic Amato sided with the association, ruling that the city was still obligated to bargain with the union over costs.