10 ILCS 5/7-7
For the purpose of making nominations in certain instances as provided in this Article and this Act, the following committees are authorized and shall constitute the central or managing committees of each political party, viz: A State central committee, whose responsibilities include, but are not limited to, filling by appointment vacancies in nomination for statewide offices, including but not limited to the office of United States Senator, a congressional committee for each congressional district, a county central committee for each county, a municipal central committee for each city, incorporated town or village, a ward committeeperson for each ward in cities containing a population of 500,000 or more; a township committeeperson for each township or part of a township that lies outside of cities having a population of 200,000 or more, in counties having a population of 2,000,000 or more; a precinct committeeperson for each precinct in counties having a population of less than 2,000,000; a county board district committee for each county board district created under Division 2-3 of the Counties Code; a State's Attorney committee for each group of 2 or more counties which jointly elect a State's Attorney; a Superintendent of Multi-County Educational Service Region committee for each group of 2 or more counties which jointly elect a Superintendent of a Multi-County Educational Service Region; a judicial subcircuit committee in a judicial circuit divided into subcircuits for each judicial subcircuit in that circuit; and a board of review election district committee for each Cook County Board of Review election district.
10 ILCS 5/7-7