S.C. Code Ann. § 11-40-190

This State pledges to and agrees with the holders of any bonds issued by the authority pursuant to this chapter that it shall not alter or limit the rights vested in the authority to fulfill the terms of any agreement made with or for the benefit of the holders of bonds or in any way impair the rights and remedies of bondholders until the bonds, together with the interest thereon, with interest on any unpaid installments of interest, and all costs and expenses in connection with any action or proceeding by or on behalf of such holders, are fully met and discharged or funds for the payment of such are fully provided. The authority may include this pledge and agreement of the State in any agreement with bondholders.