Section 9. Amendment by initiative. (1) The people may also propose constitutional amendments by initiative. Petitions including the full text of the proposed amendment shall be signed by at least ten percent of the qualified electors of the state. That number shall include at least ten percent of the qualified electors in each of two-fifths of the legislative districts.
     (2) The petitions shall be filed with the secretary of state. If the petitions are found to have been signed by the required number of electors, the secretary of state shall cause the amendment to be published as provided by law twice each month for two months previous to the next regular state-wide election.
     (3) At that election, the proposed amendment shall be submitted to the qualified electors for approval or rejection. If approved by a majority voting thereon, it shall become a part of the constitution effective the first day of July following its approval, unless the amendment provides otherwise.