Black Representation Under Cumulative Voting in IL
From 1870 to 1980, Illinois used cumulative voting to elect member of the State House of Representatives. Candidates ran in three-seat constituencies. These three-seat house districts also were used to elect a single state senator.
This chart records how many black legislators were elected in each election between 1900 and 1978. Cumulative voting clearly provided a powerful gateway for black representation: black candidates were elected earlier than likely would have happened with single-member districts and, for most of the period, likely in bigger numbers. The state senate lagged far behind in black representation until the mid-1960s, when reapportionment in the wake of Supreme Court rulings on "one person, one vote" led to more equitable representation of Chicago.
These numbers do not provide details about these black representatives and their district. Based on the state senate results, however, it is nearly certain that most black members of the House of Representatives in 1954-1964 were elected in white-majority districts. After 1964, blacks in the state senate and house probably were represented in comparable proportions because there were so few districts outside of Chicago where blacks made up at least 25% of the adult population (25% being the share of the vote necessary to ensure winning a seat). Put into a 21st century context, the history of cumulative voting in Illinois suggests that dispersed populations -- such as blacks in much of the South and Asian Americans and Latinos in much of the country -- would do well with cumulative voting and proportional systems.
(Notes: 1) Three black state legislators served a total of 14 terms from 1877-1895. 2) There were also interesting patterns of black legislators' service. In the senate, all legislators served consecutive years of service. In the house, however, numerous legislators had discontinuous service, likely indicating real competition -- probably in primaries.)