By a 4-3 vote, the Illinois Supreme Court threw out a lawsuit that the legislative remap drawn up by the state's Democratic-controlled General Assembly violated the state constitution. The court dismissed the lawsuit, filed by Senate Minority Leader Christine Rodogno (R-Lemont) and House Minority Leader Tom Cross (R-Oswego), without explanation. The vote ran along party lines.

The March 20 Illinois primary took place under the new map. While the redistricting may not be unconstitutional, it did improve the prospects for Chicagoland Democrats picking up seats in Congress.