Amendments to this constitution may be proposed by a two-thirds vote of each house of the legislature. The lieutenant governor shall prepare a ballot title and proposition summarizing each proposed amendment, and shall place them on the ballot for the next general election. If a majority of the votes cast on the proposition favor the amendment, it shall be adopted. Unless otherwise provided in the amendment, it becomes effective thirty days after the certification of the election returns by the lieutenant governor. [Amended 1970, 1974]