Politics in Chicago through most of the 20th century was dominated by the Democratic Party. Organized crime and political corruption were persistent concerns in the city. Democrats have usually dominated city politics. Thus the city was the political base for presidential nominees Stephen Douglas (1860), Adlai Stevenson II (1952 and 1956), and Barack Obama, who was nominated and elected in 2008.
In 1855, Chicago Mayor Levi Boone threw Chicago politics into the national spotlight with some dry proposals that led to the Lager Beer Riot by the wets.[full citation needed]
The 1860 Republican National Convention in Chicago nominated home-state candidate Abraham Lincoln. During the 1880s, 1890s, and early 20th century, Chicago also had an underground radical tradition with large and highly organized socialist, communist, anarchist and labor organizations. The Republicans had their own machine operations, typified by the "blonde boss" William Lorimer, who was unseated by the U.S. Senate in 1912 because of his corrupt election methods.
The political environment in Chicago in the 1910s and 1920s let organized crime flourish to the point that many Chicago policemen earned more money from pay-offs than from the city. Before the 1930s, the Democratic Party in Chicago was divided along ethnic lines - the Irish, Polish, Italian, and other groups each controlled politics in their neighborhoods. Under the leadership of Anton Cermak, the party consolidated its ethnic bases into one large organization. With the organization behind, Cermak was able to win election as mayor of Chicago in 1931, an office he held until his assassination in 1933.
The modern era of politics was dominated by machine politics in many ways, and the Cook County Democratic Party was honed by Richard J. Daley after his election in 1955. Richard M. Daley, his son, later became mayor and served from 1989 to 2011. Daley announced on September 7, 2010 that he would not be seeking re-election. Daley was succeeded by former Obama White House Chief of Staff Rahm Emanuel.
The New Deal of the 1930s and the Great Society of the 1960s gave the Democratic Party access to new funds and programs for housing, slum clearance, urban renewal, and education, through which to dispense patronage and maintain control of the city. Machine politics persisted in Chicago after the decline 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. This included African Americans and Latinos. In the Lakeview/Uptown 46th Ward, the first Latino to announce an aldermanic bid against a Daley loyalist was Jose Cha Cha Jimenez, founder of the Young Lords.
The police corruption that came to the light from the Summerdale Scandals of 1960, in which police officers kept stolen property or sold it and kept the cash, was another black eye on the local political scene of Chicago. Eight officers from the Summerdale police district on Chicago's Northwest Side were accused of operating a large-scale burglary ring.
The Daley faction, with financial help from Joseph P. Kennedy, Sr., helped elect John F. Kennedy to the office of President of the United States in the 1960 presidential election.
Chicago politics have also hosted some very publicized campaigns and conventions. The Democratic Party decided on Harry S. Truman as the vice-presidential candidate at the 1944 Democratic National Convention. The 1968 Democratic National Convention was the scene of mass political rallies and discontent, leading to the trial of the Chicago Seven. Seven defendants—Abbie Hoffman, Jerry Rubin, David Dellinger, Tom Hayden, Rennie Davis, John Froines, and Lee Weiner—were charged with conspiracy, inciting to riot, and other charges related to protests.
Home-town columnist Mike Royko wrote satirically that Chicago's motto (Urbs in Horto or "City in a Garden") should instead be Ubi est mea, or "Where's Mine?"
The shock election of six Democratic Socialists of America to the council in 2019 was as the largest socialist electoral victory in modern American history.
Chicago has a long history of political corruption, dating to the incorporation of the city in 1833. It has been a de facto monolithic entity of the Democratic Party from the mid-20th century onward. In the 1980s, the Operation Greylord investigation resulted in the indictments of 93 public officials, including 17 judges. Research released by the University of Illinois at Chicago reports that Chicago and Cook County's judicial district recorded 45 public corruption convictions for 2013, and 1,642 convictions since 1976, when the Department of Justice began compiling statistics. This prompted many media outlets to declare Chicago the "corruption capital of America". Gradel and Simpson's Corrupt Illinois (2015) provides the data behind Chicago's corrupt political culture. They found that a tabulation of federal public corruption convictions make Chicago "undoubtedly the most corrupt city in our nation", with the cost of corruption "at least" $500 million per year.