Michigan state workers are challenging a new law that requires them to pay 4% of their salary to their defined-benefit pension plan or to opt out entirely. The unions also successfully challenged an earlier change that required them to pay 3% of their salary to health care. The five unions that filed the lawsuit represent 34,000 state workers, and they say that the change in unconstitutional under Michigan law.
See "State workers' lawsuit says pension law isn't constitutional", Paul Egan, Detroit Free Press, February 13, 2012