A group of democracy advocates and Wisconsin voters challenged Wisconsin’s congressional redistricting map in state court as a violation of the Wisconsin Constitution.  They allege that the map is an anti-competitive gerrymander designed to suppress competition and that makes it nearly impossible to oust existing incumbents. Yet the Circuit Court dismissed their case without giving the plaintiffs an opportunity to substantiate their claims. The plaintiffs appealed to the Wisconsin Supreme Court, and in September 2026, CAC, along with Stafford Rosenbaum LLP, filed an amici curiae brief on behalf of political scientists Kosuke Imai, Christopher T. Kenny, Phil Jones, and John Griffin in support of the plaintiffs. Our brief makes two principal points.

First, anti-competitive gerrymanders harm fundamental democratic principles. Here, the plaintiffs allege a textbook example of an anti-competitive gerrymander designed to protect incumbents of both parties from political competition. Voters deserve a meaningful choice between candidates, not a rigged system where the deck is stacked in favor of incumbent candidates. Otherwise, they cannot hold their elected representatives accountable, and incumbents will not be as responsive to their constituents.

Second, political science offers reliable, judicially-manageable tools that courts can use to identify and address anti-competitive gerrymanders. By comparing maps enacted by lawmakers against computer-generated maps that satisfy all applicable state districting criteria, political scientists can identify gerrymanders and analyze their effects. This basic method of scientific analysis has been repeatedly approved by courts in a wide range of gerrymandering cases.