"Public office" means a position created by or under the Constitution or laws of this State, the occupant of which is charged with the exercise of some portion of the sovereign power of this State. The term "public office" shall include members of the public body, but it shall not include organizational positions filled by members thereof, whether established by law or by a public body itself, that exist to assist the body in the conduct of its business.
"Quasi-adjudicative body" means an administrative body charged by law or ordinance with the responsibility to conduct hearings, receive evidence or testimony and make determinations based thereon, but does not include local electoral boards when such bodies are considering petition challenges.
5 ILCS 120/2