Wis. Stat. § 229.76: State pledge.

The state pledges to and agrees with the bondholders, and persons that enter into contracts with a district under this subchapter, that the state will not limit or alter the rights and powers vested in a district by this subchapter, including the power to obtain a loan from the department of administration upon the request of the district under s. 16.09 (5), before the district has fully met and discharged the bonds, and any interest due on the bonds, and has fully performed its contracts, including any lease agreement with a professional baseball team with respect to baseball park facilities, unless adequate provision is made by law for the protection of the bondholders or those entering into contracts with a district.