In Illinois, the state legislature draws congressional districts, subject only to federal constitutional and statutory limitations. The legislature also has the first opportunity to draw state legislative districts, but if it cannot agree on a plan, a backup commission with a random tiebreaking vote will draw the lines.
Article IV of the Illinois Constitution governs redistricting. In the 2001 cycle, control was divided, with a Republican Governor, a Senate controlled by Republicans, and a House controlled by Democrats. The state legislative redistricting process deadlocked, and control fell to the backup commission, controlled by Democrats after the random draw of a Democratic tiebreaking commissioner.
View testimony of Justin Levitt before the Illinois Senate Redistricting Committee (October 2009)
View an analysis of Illinois' 2009 redistricting proposals: HJ 16 and SC 69