60 ILCS 1/45-55
In (i) counties having a population of more than 3,000,000, the township central committee of a political party composed of the elected township committeeman and his or her appointed precinct committeemen and (ii) townships with a population of more than 15,000 in counties with a population of 3,000,000 or less, the township central committee of a political party composed of the precinct committeemen may, with respect to any regular township election, determine that its candidates for township offices shall be nominated by primary in accordance with the general election law, rather than in the manner provided in Sections 45-5 through 45-45. If the township central committee makes that determination, it must file a statement of the determination with the county clerk no later than August 15 preceding the township election. If the township or any part of the township is within the jurisdiction of a board of election commissioners, the township central committee shall promptly notify the board of election commissioners of the determination. Upon the filing of the determination by the township central committee of a political party, the provisions of the general election law shall govern the nomination of candidates of that political party for township offices for the election with respect to which the determination was made.
60 ILCS 1/45-55