Wisconsin gerrymandering lawsuit could redraw legislative maps

In November 2016, a panel of federal district judges struck down Wisconsin’s 2011 state legislative district maps as an unconstitutional gerrymander. “It is clear that the drafters got what they intended to get,” Judge Kenneth Ripple wrote in the 2-1 decision. “There is no question that Act 43 was designed to make it more difficult for Democrats, compared with Republicans, to translate their votes into seats.”

The judges did not rule on whether the plaintiff’s proposed measuring stick — the “efficiency gap,” which measures how many votes are “wasted” in a given election — is the proper metric to determine an illegal map. Instead, they asked both sides to submit evidence for how the maps should be rectified.
Ultimately, this case, as well as the legal fate of the efficiency gap, will probably be decided by the U.S. Supreme Court, which last ruled on gerrymanders in 1986, stating they could be illegal if too severe, but without clarifying how severity could or should be measured.
The efficiency gap, proposed by Nicholas Stefanopolous, an assistant professor at the University of Chicago Law School, and Eric McGhee, a research fellow at the Public Policy Institute of California, is one such standard. Under the gap, a vote is considered “wasted” if cast for the losing candidate or cast for the winning candidate above and beyond what’s necessary to win. Wasted votes can be brought about by either “packing” (concentrating a party’s voters into one district) or “cracking” (diluting a party’s votes across multiple districts).
According to a brief from Eric Petry, a research/program associate at the Brennan Center for Justice (part of New York University’s School of Law), to determine whether the gap uncovers an illegal gerrymander, you have to determine each party’s total number of net “wasted” votes, then divide that figure by the total number of votes cast.
According to Stefanopoulos and McGhee, fairly drawn maps should show efficiency gaps of less than 8 percent, meaning any gap of 8 percent or greater reveals an illegal gerrymander.
Redistricting trends in Midwest
Concerns about gerrymandering have led to a series of proposed ballot measures in the Midwest. 
In 2015, Ohio voters changed their state’s process for drawing state legislative maps to prevent gerrymandering and to make it more bipartisan. In addition to creating a seven-member redistricting commission with membership from both political parties, Ohio’s enacted ballot measure, which will take effect with the next round of redistricting, explicitly bans maps for the General Assembly that are “drawn primarily to favor or disfavor a political party.”
This past November, South Dakotans rejected Amendment T, which would have reassigned legislative redistricting from the legislature to an independent commission composed of nine registered voters (with no more than three being from the same party). And in August 2016, in a 4-3 decision, the Illinois Supreme Court stopped a proposed state constitutional amendment that would have asked voters whether to switch from a legislatively drawn map to a commission-drawn map.
In most Midwestern states, the redrawing of state legislative and U.S. congressional districts remains under the authority of state legislatures.
But advocates of reform often cite Iowa as one model for reform. There, the state’s nonpartisan Legislative Services Agency develops the state and federal maps. These maps must be approved or rejected — without modification — by the legislature. If lawmakers fail to approve the first two plans, they may amend the third map as it would any other bill. The remaps also must be approved by the Iowa governor.
Stateline Midwest: January 20174.53 MB