Rob Yablon recently posted a terrific new article, Gerrylaundering, criticizing mapmakers who prioritize changing districts as little as possible when they redistrict. Gerrylaundering, Yablon points out, is especially pernicious when the prior plan was a gerrymander. In that case, while nominally neutral, gerrylaundering in fact perpetuates the gerrymander for another decade.

An interesting case of mapmakers trying to get a court to gerrylaunder is ongoing in Wisconsin. Wisconsin’s current maps are among the most gerrymandered in modern American history. But Republican legislators can’t just redraw those maps because the governor, Tony Evers, is a Democrat. So Republicans have gone to the Wisconsin Supreme Court asking it to gerrylaunder for them. According to the legislature’s brief, the court should either adopt the legislature’s new proposed maps (which Evers is sure to veto) or apply a “least change” principle to Wisconsin’s existing gerrymanders.

Harvard Law School’s new Election Law Clinic (in which I teach) filed an amicus brief in this matter on behalf of the plaintiffs from last decade’s Whitford v. Gill litigation. The brief notes that “least change” is nowhere to be found in the Wisconsin Constitution’s list of redistricting criteria. Nor have Wisconsin’s previous line-drawers (legislative or judicial) ever tried to keep old districts intact. Outside Wisconsin as well, least-change is a vanishingly rare and disfavored criterion. Almost no states include it in their redistricting requirements and almost no courts choose to use it — precisely because of how it extends existing biases into the future.