After the first election of state officials following the effective date of this constitution, the legislature may provide, by law enacted by two-thirds of the elected members of each house, for appointment, in lieu of election, of the commissioner of agriculture, the commissioner of insurance, the superintendent of education, the commissioner of elections, or any of them. In that event, the legislature shall prescribe qualifications and method of appointment and by similar vote, may provide by law for the merger or consolidation of any such office, its department, and functions with any other office or department in the executive branch. No action of the legislature pursuant hereto shall reduce the term or compensation of any incumbent elected official. By law enacted by two-thirds of the elected members of each house, the legislature may reestablish any such office as elective and, in that event, shall prescribe qualifications.