Unless otherwise required by law, all proposed constitutional amendments and any other measure or question that is to be submitted to a vote of the people, or any petitions requesting that a measure or question be submitted to a vote of the people, if applicable, shall be filed with the official or agency responsible for preparing the ballots for the election no later than 70 days prior to the election at which the amendment, measure or question will appear on the ballot. No later than the end of the next business day after a proposed measure is filed with a school district clerk under this section, the clerk shall file a copy of the measure or question with the clerk of each county having territory within the school district.