Illinois

Illinois’ congressional lines are drawn by the state legislature, as a regular statute, subject to gubernatorial veto.

Illinois’ legislature is also primarily responsible for drawing state legislative lines.  If the legislature fails to pass a plan, authority falls to an eight-member backup commission, in place since 1980. Each of the four legislative leaders (majority and minority leader in each legislative house) chooses two commissioners apiece: one legislator and one member of the public; at most four may have the same party affiliation.   If a majority of those eight commissioners cannot agree on a plan, the state Supreme Court submits two individuals from different political parties to the Secretary of State, and the Secretary of State will randomly choose one of the two to serve as a tiebreaker on the commission. In the 2000 cycle, the name of the commission’s tiebreaker was selected by pulling a commissioner’s name from a replica of Lincoln’s stovepipe hat. [Ill. Const. art. IV, § 3]

The Illinois Supreme Court has exclusive jurisdiction to hear challenges to state legislative plans in state court. [Ill. Const. art. IV, § 3]

Illinois state law does not impose a particular deadline for drawing congressional lines, though candidates must file for congressional primary elections by Mar. 14, 2022. [10 Ill. Comp. Stat. § 5/7-12(1)]  The legislative session began on Jan. 13, 2021, and runs through the end of the calendar year.

The legislature’s deadline for drawing state legislative lines was June 30, 2021; if the legislature failed to pass a plan by then, the backup commission was supposed to be convened. The commission’s first eight members had until August 10, 2021, to produce a plan, whereupon the tiebreaker will be appointed. The final deadline for the nine-member backup commission was Oct. 5, 2021. [Ill. Const. art. IV, § 3(b)]  Candidates were required to file for state legislative primary elections by Mar. 14, 2022. [10 Ill. Comp. Stat. § 5/7-12(1)]

Illinois prohibits redrawing state legislative lines mid-decade, before the next Census; there is no similar provision pertaining to congressional lines. [Ill. Const. art. IV, § 3(b); Mooney v. Hutchinson, 50 N.E. 599 (Ill. 1898)]

Legislative redistricting committees must hold at least one public hearing in each of four distinct geographic regions of the state, in order to receive testimony from the public. [10 Ill. Cons. Stat. § 125/10-5]  The legislature may alter these requirements by statute.

Public hearing materials for the Senate and House redistricting committees for the 2020 cycle can be found here and here, respectively.  Both committees provided web tools for members of the public to submit feedback to the committees.

Like all states, Illinois must comply with constitutional equal population requirements.  Starting in 2025, Illinois also adjusts census data for state legislative districts in order to count incarcerated individuals at their last known residence before incarceration.  [730 Ill. Cons. Stat. § 205/2-1 et seq.]

Also like all states, Illinois must abide by the Voting Rights Act and constitutional rules on race.  For state legislative districts, state law further directs the redistricting body to create, where legally and pragmatically possible, districts that allow racial or language minority communities to elect — or influence the election of — the candidates of their choice, even if no comparable district would be required by the federal Voting Rights Act.  That requirement was implemented after the last cycle’s redistricting, and has not yet been interpreted by the courts.  [10 Ill. Cons. Stat. §§ 120/5-5]  The legislature may alter these requirements by statute.

For Illinois’ state legislative lines, the state constitution further requires that districts be contiguous and reasonably compact. There are no similar requirements for congressional lines. [Ill. Const. art. IV, § 3(a); People ex rel. Burris v. Ryan, 588 N.E.2d 1023, 1028 (Ill. 1991); Schrage v. State Bd. of Elections, 430 N.E.2d 483 (Ill. 1981)]

The Illinois legislature passed a congressional plan (HB 1291) on Nov. 1, 2021, which the governor signed on Nov. 23, 2021.

For the state legislative map, using American Community Survey (ACS) data because of the delay in Census results, the legislature passed a state legislative plan (HB 2777) on May 28, 2021, which the governor signed on June 4, 2021.  After the release of Census data, the legislature passed a new state legislative plan (SB 927) on Aug. 31, 2021, which the governor signed on Sept. 24, 2021.

The June state legislative plan using ACS data was struck by a federal court on Oct. 19, 2021, as unconstitutionally malapportioned.  [McConchie v. Scholz, 567 F.Supp.3d 861 (N.D. Ill. 2021)]  Challenges to the September state legislative plan in state and federal were rejected.  [McConchie v. Scholz, 577 F.Supp.3d 842 (N.D. Ill. 2021); McCombie v. Ill. State Bd. of Elections, 2025 Ill. 131480 (Ill. 2025)]  It does not appear that the congressional plan was challenged in court.

The Illinois legislature passed a congressional plan (SB 1178) on May 31, 2011, which the governor signed on June 24, 2011.

The Illinois legislature passed a state legislative plan (SB 1177) on May 27, 2011, which the governor signed on June 3, 2011.

The congressional plan was challenged in federal court, and the state legislative plan was challenged in federal and state court. The challenges were ultimately rejected. [Cross v. Ill. State Bd. of Elections, No. 113840 (Ill. June 7, 2012); Radogno v. Ill. State Bd. of Elections, 836 F. Supp. 2d 759 (N.D. Ill. 2011), aff’d, 133 S. Ct. 103 (2012); Comm. for a Fair and Balanced Map v. Ill. State Bd. of Elections, 835 F. Supp. 2d 563 (N.D. Ill. 2011); League of Women Voters v. Quinn, No. 1:11-cv-05569, 2011 WL 5143044 (N.D. Ill. Oct. 28, 2011), aff’d, 132 S. Ct. 2430 (2012)]

The Illinois legislature passed a congressional plan (HB 2917) on May 30, 2001, which the governor signed the next day.  It could not agree on a state legislative plan, however, and the process fell to a backup commission. That commission — with its ninth member appointed by drawing a name from a replica of Lincoln’s stovepipe hat — approved a state legislative plan on Sept. 25, 2001.

The congressional plan and state legislative plan were both challenged in state court, and the state legislative plan was challenged in federal court. The challenges were ultimately rejected. [Campuzano v. Ill. State Bd. of Elections, 200 F. Supp. 2d 905 (N.D. Ill. 2002); Beaubien v. Ryan, 762 N.E.2d 501 (Ill. 2001); Cole-Randazzo v. Ryan, 762 N.E.2d 485 (Ill. 2001)]