The city of Chicago, the largest municipality in Cook County, elects committeepeople (known as "committeemen" until 2018) from each of its 50 wards.
[1][5][6] Each established party in Cook County, currently Democrats, Republicans and Libertarians, elects its own committeeperson.
Replacements for some other vacancies are selected through other processes: vacated United States Senate posts are appointed by the Illinois Governor and vacated Chicago City Council posts are appointed by the Mayor of Chicago.
[9][10][11] Operationally in Chicago, the committeeperson plays an important role in ward politics.
Sometimes a committeeperson accumulates sufficient influence to place their loyalists into political positions outside of the ward.