The Cook County Democratic Party is a political party which represents voters in 50 wards in the city of Chicago and 30 suburban townships of Cook County. The organization has dominated Chicago politics (and consequently, Illinois politics) since the 1930s. It relies on a tight organizational structure of ward and township committeemen to elect candidates. At the height of its influence under Richard J. Daley in the 1960s, it was one of the most powerful political machines in American history. Party members have been convicted of public corruption. By the beginning of the 21st century the party had largely ceased to function as a machine due to the decline of political patronage following the issuing of the Shakman Decrees. The current Chairman is Joseph Berrios.