U.S. Census Bureau Counts Confirm that Democrats’ Redistricting Plan Is Unconstitutional and Unlawful

CHICAGO, IL – The official 2020 decennial counts released by the U.S. Census Bureau on August 12 confirm that the Democrats’ redistricting plan, H.B. 2777, violates the U.S. Constitution and federal law, as well as comparable provisions of the Illinois Constitution. Accordingly, no lawful redistricting plan was effective on June 30, 2021. The Illinois Constitution is clear that responsibility for the plan has shifted to the bipartisan Legislative Redistricting Commission.

“Just as we predicted, the maps that were drawn by Illinois Democrats in a closed room and without public input, and signed by Governor Pritzker, have proven to be unusable and unlawful given the release of the U.S. Census data,” said House Republican Leader Jim Durkin (R-Western Springs). “It is now up to the Legislative Redistricting Commission to draw the fair maps our state so desperately needs.”

The Democrats’ proposed House districts have population counts ranging from 92,390 (District 83) to 124,836 (District 5)—a difference of 32,446. Based on a test directed by the U.S. Supreme Court, that difference represents a total population range of 29.88 percent, which is three times the maximum range allowed by federal law. Because the Democrats’ plan unequivocally violates federal law, it is and will be declared void.

“Despite bipartisan pleas to wait for the Census number like 48 other states, Illinois Democratic politicians that were led by Governor Pritzker ignored the voting rights of their own constituents in an attempt to hold absolute power for another decade,” said Illinois Senate Republican Leader Dan McConchie (R-Hawthorn Woods). “By breaking his promise and signing this map that has now been proven to be widely inaccurate, Governor Pritzker once again sided with political insiders against the people of Illinois.”


  • The US Census Bureau released the official 2020 decennial census counts, which is sometimes called P.L. 94-171 data, on August 12, 2021. Those counts were released in “legacy format,” which means that they are capable of being read by computer programs commonly used in redistricting and by demographers and statisticians. The Bureau will release interactive data for public consumption later in September, but the counts will be unchanged.
  • Experts and consultants retained by the House and Senate Republican Caucuses computed the population counts for each district in the Democrats’ redistricting plan (H.B. 2777). This is done by overlaying the Democrats’ district boundaries on the population counts.
  • This is a simple tabulation. Any qualified person attempting to perform the same calculation will arrive at the same counts by district. Unlike the use of ACS estimates, the Census counts are reported to the block-level, so no manipulation, assumptions, or algorithms are needed.
  • The U.S. Supreme Court provided instructions for calculating the so-called “maximum population deviation” in Evenwel v. Abbott(2016), based on an earlier 1975 case (Chapman v. Meier). The maximum population deviation of a plan is the sum of the percentage deviations of the most-populated and least-populated districts from perfect population equality.
  • The Democrats’ redistricting plan has a maximum population deviation of 29.88 percent, which is three times the maximum deviation allowed by federal law (10 percent). The least-populated House district is House District 83 (92,390 people), which is 14.91 percent below the average district population, and the most-populated House district is House District 5 (124,836), which is 14.97 percent above the average district population.
  • This total deviation of approximately 30 percent is within the range forecasted in the Republican Leaders’ complaint filed in federal court. Based on simulations of the use of 2005-2009 ACS estimates compared to the 2010 decennial census counts, we had forecasted a deviation of at least 23 percent.
  • Because the Democrats’ plan violates federal law, the Republican Leaders have asked the federal court to declare H.B. 2777 void, meaning it was never of any force or effect. The Illinois Constitution is clear that if no valid plan was in effect on June 30th, responsibility for enacting a plan shifts to the bipartisan Legislative Redistricting Commission.
Dan McConchie

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