Wisconsin Gov. Scott Walker's signature law slashing collective bargaining rights for public employees has already taken one judicial hit, and now it's taken another:

Dane County Circuit Judge Juan Colas ruled that the law violates both the state and U.S. Constitution and is null and void. The ruling comes after a lawsuit brought by the Madison teachers union and a union for Milwaukee city employees.

Walker spokesman Cullen Werwie said he was confident the decision will be overturned on appeal.