Arizona Constitution Art. VII § 10. Direct primary election law

Section 10. The Legislature shall enact a direct primary election law, which shall provide for the nomination of candidates for all elective State, county, and city offices, including candidates for United States Senator and for Representative in Congress. Any person who is registered as no party preference or independent as the party preference or who is registered with a political party that is not qualified for representation on the ballot may vote in the primary election of any one of the political parties that is qualified for the ballot.