Cal. Const. art. II § 10 : — VOTING, INITIATIVE AND REFERENDUM, AND RECALLSection 10

(a) An initiative statute or referendum approved by a majority of votes cast thereon takes effect on the fifth day after the Secretary of State files the statement of the vote for the election at which the measure is voted on, but the measure may provide that it becomes operative after its effective date. If a referendum petition is filed against a part of a statute, the remainder of the statute shall not be delayed from going into effect.
(b) If provisions of two or more measures approved at the same election conflict, the provisions of the measure receiving the highest number of affirmative votes shall prevail.
(c) The Legislature may amend or repeal a referendum statute. The Legislature may amend or repeal an initiative statute by another statute that becomes effective only when approved by the electors unless the initiative statute permits amendment or repeal without the electors' approval.
(d) Before circulation of an initiative or referendum petition for signatures, a copy shall be submitted to the Attorney General who shall prepare a title and summary of the measure as provided by law.
(e) The Legislature shall provide for the manner in which a petition shall be circulated, presented, and certified, and the manner in which a measure shall be submitted to the electors.

Cal. Const. art. II § 10

Amended by Proposition 71, approved by the voters at the 6/5/2018 election.