In July 2011, Illinois Republicans challenged the new U.S. House districts in Illinois, on the basis that they are a severe partisan gerrymander and also that they violate the voting rights of Hispanic voters. Recently the plaintiffs asked a federal court in Washington, D.C., to enforce a subpoena on the Democratic Congressional Campaign Committee. Republicans want to know the extent to which the national Democratic Party helped draw up the new Illinois district lines. The Illinois legislature passed its plan this year with no public hearings. See this story. The case is Committee for a Fair & Balanced Map v Illinois State Board of Elections, 1:11-cv-05065. It is before a 3-judge court in Illinois composed of Judges John Tinder, Robert Miller and Joan Lefkow.
At least four cases are pending in various courts against the Illinois congressional and legislative redistricting plan, including a League of Women Voters case. See the web page http://redistricting.lls.edu for a list of all such cases pending in all 50 states. Here is a link to that page. Thanks to Rick Hasen for making me aware of that web page, which is the creation of Associate Professor of Law Justin Levitt.