The government of the City of Chicago, Illinois, is divided into executive and legislative branches. The Mayor of Chicago is the chief executive, elected by general election for a term of four years. The mayor appoints commissioners and other officials who oversee the various departments. In addition to the mayor, Chicago's two other citywide elected officials are the clerk and the treasurer.

The Chicago City Council is the legislative branch and is made up of 50 aldermen, one elected from each ward in the city. The council enacts local ordinances and approves the city budget. Government priorities and activities are established in a budget ordinance usually adopted each November. The council takes official action through the passage of ordinances and resolutions.

Politics

One stereotype about Chicago is certainly true: its citizens love politics. A high number of people know not only who controls their ward but who represents them in Congress and how they were elected to office. This deeply ingrained political culture creates an environment where elections could be described more as spectator sport than anything else.

During the Civil War, Chicago, populated heavily from Northern States, was a major supplier of goods and manpower to the Union Army, but southern Illinois, which at the time of the war was the population center of the state with a citizenry drawn from the Southern states, was more supportive for an alliance with the Confederacy. Today there are prevailing attitudes of disdain between the dense industrial Chicago area and rural downstate Illinois. This helped to foster a political atmosphere of us vs. them, meaning Chicagoans and Downstaters, that still plagues the political and social life of both the city and the state.

During much of the last half of the 19th Century, Chicago's politics were dominated by a growing Democratic Party organization dominated by ethnic ward-healers. During the 1880s and 1890s, Chicago also had a powerful radical tradition with large and highly organized socialist, anarchist and labor organizations.

The modern era of politics is still in many ways dominated by machine politics, a style honed and perfected by Richard J. Daley after his election in 1955. Further evidence of this is the fact that his son, Richard M. Daley, is the current mayor.

Richard J. Daley's mastery of machine politics preserved the Chicago Democratic Machine long after the demise of similar machines in other large American cities. During much of that time the city administration found opposition mainly from a liberal "independent" faction of the Democratic Party. The independents finally won control of city government in 1983 with the election of Harold Washington. Since Washington's death, Chicago has returned to the leadership of the Democratic organization led by Richard M. Daley, although it may differ from the previous ward-based organization, as it relies on other groups, such as the Hispanic Democratic Organization.

For much of the 20th century, Chicago has been considered one of the largest Democratic strongholds in the United States. The citizens of Chicago have not elected a Republican mayor since 1927, when William Thompson was voted into office. Today only one aldermen member is Republican.