Illinois constitution
Article XIII
Section 3

Each prospective holder of a State office or other State position created by this Constitution, before taking office,
shall take and subscribe to the following oath or affirmation:
"I do solemnly swear (affirm) that I will support the Constitution of the United States, and the Constitution of
the State of Illinois, and that I will faithfully discharge the duties of the office of .... to the best of my ability."