Data scientists help courts grapple with increasingly divisive maps

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Photo of Justice Samuel A. Alito, Jr. by Shutterstock

The August workshop of the Metric Geometry and Gerrymandering Group drew as many as 600 participants, organizers estimate. Three out of four were in math-related fields or other academic disciplines.

There were about 100 K-12 educators, for whom there were some breakout sessions regarding teaching about gerrymandering and perhaps getting young people involved in the effort to solve it. There were students, community advocates and, of course, lawyers.

(The ABA Journal did not attend the “Geometry of Redistricting” workshop. Videos of many of the sessions are available online.)

Duchin of Tufts kicked off the workshop with a rudimentary lesson about redistricting and gerrymandering.

She noted that the word gerrymandering originated with an 1812 political cartoon that derided a map drawn under Massachusetts Gov. Elbridge Gerry. The cartoon suggested that one district in Boston’s North Shore had the shape of a reptile.

“The cartoon was designed to lampoon this as a dragon or a salamander,” Duchin told the workshop. “That’s what gave us the name ‘gerrymander’—Gerry and salamander became the gerrymander.”

Gerry’s name has been linked with the practice ever since. (For more, see A Move Toward ‘1 Person, 1 Vote, February.)

There are still strangely shaped districts that strike many observers as classic forms of gerrymandering, such as Pennsylvania’s 7th Congressional District (known as “Goofy kicking Donald Duck”) and Illinois’ 4th Congressional District (known as “the Earmuffs”). Those districts, however, have not been struck down.

As professional redistricting mapmakers use more sophisticated data and tools, gerrymandering can be carried out in districts without crazy shapes.

“You can have districts that are perfectly compact that are nonetheless very unfair to one party,” says McGhee, a research fellow at the Public Policy Institute of California in San Francisco.

Two of the most widely used forms of gerrymandering today have the snappy names “packing” and “cracking.”

With packing, the party in control of the map packs as many voters of the opposing party into a handful of districts, which they’ll win easily with so-called wasted votes. With cracking, the mapmaker spreads the minority party’s voters across multiple districts in a way such that they don’t have a chance to win.

“So by making those two things play off each other—packing your opponents into districts, and then cracking and dispersing the ones left over—that’s a way to maximize your representation,” Duchin said at the workshop.

She went on to outline the high stakes and sophistication of current methods.

“The threat of gerrymandering, or precision drawing of voting districts in particular to meet some agenda … is really intensified” today, Duchin said. “It’s intensified by technology, it’s intensified by data and better handling of big data sets. We have GIS, or geographic information systems, we have maps that are manipulable down to the house level, and we have very rich voter-data files.”

“We can now know an enormous amount of information about voters—age, race, income, political preference and so on,” Duchin continued. “And if you overlay the data on the map, you can rig maps to get all kinds of outcomes. And that’s what we’re here to talk about.”

The lessons quickly got more complicated. They included the legal background of redistricting and gerrymandering from the likes of Steve Ansolabehere, a Harvard Law School government professor; Ellen D. Katz, a law professor at the University of Michigan; and Kristen Clarke, president of the Lawyers’ Committee for Civil Rights Under Law.

Then the mathematics began. There was a lesson called “Computational Social Science” by Wendy K. Tam Cho, a multidiscipline professor (Asian-American studies, law, political science and statistics) at the University of Illinois at Urbana-Champaign, a leading academic on redistricting.

There was also “Geometry of Data: Algorithmic Approaches to Gerrymandering” by Solomon of MIT. And also “The Quantitative Anatomy of a Voting Rights Case,” by Megan Gall, then the staff social scientist of the Lawyers’ Committee and now with the NAACP Legal Defense and Educational Fund.

“As one of my lawyer colleagues likes to say, ‘You have to get a little bit ‘mathy,’ ” in tackling gerrymandering issues, Gall told the workshop.


The chief goal of the MGGG and the workshop— as well as a series of regional workshops happening around the country—is to get mathematicians, engineers, social scientists and other scientists involved in cases.

Besides the general sessions, there were specialized training tracks for participants to work on technical solutions (or “hacks”) and to train the science crowd to become expert witnesses in court cases.

Progressive-minded groups such as the Lawyers’ Committee, the LDF and the Campaign Legal Center (which challenged the Wisconsin remap) are most likely to intervene. But workshop organizers took pains to make clear that their approach is nonpartisan.

Clark Bensen, a longtime Republican redistricting consultant, was a panelist at the August workshop. Misha Tseytlin, the Wisconsin solicitor general who defended the Republican-controlled legislature’s map in the Supreme Court just days earlier, was a panelist at an October regional workshop at the University of Wisconsin at Madison. And Cho of the University of Illinois had been an expert witness last year defending a Republican-drawn remap in Pennsylvania.

Still, organizers acknowledge that they are more likely to work with civil rights and progressive groups challenging the various forms of gerrymandering.

“We have strong interdisciplinary support in the academic community, and we continue to strengthen our work with civil rights organizations and community leaders,” Duchin said in a statement released by Tufts’ communications office. (Duchin declined to be interviewed for this article.)

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Mark Walsh is a freelance writer based in Washington, D.C.

This article was published in the April 2018 issue of the
ABA Journal with the title "Boundary Lines: Data scientists help courts grapple with increasingly divisive maps."

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