Gerrymandering and the Extent of Democracy in America (2018-2019)

Gerrymandering has been present in our democracy since the early 19th century. Courts have struck down district maps that clearly disadvantage racial minorities, but they have often declined to intervene in cases where maps intentionally favor a political party, in part because they lack a credible way of assessing such claims.

In 2012, Math professor Jonathan Mattingly watched this dynamic play out in North Carolina, where Republicans won nine of the 13 seats for the U.S. House of Representatives, even though Democrats received 51% of the votes. Interested in exploring gerrymandering, Mattingly partnered with an undergraduate on a summer research project. Using votes cast in the 2012 election to evaluate hundreds of alternative district maps, they were unable to find a single map that led to the same outcome.

A series of Data+ summer teams in 2015 and 2018 extended the analysis to other states, and several external partners joined the effort. In 2018-2019, this project team compared districting plans across states, analyzed the effectiveness of statistical tests currently used to detect gerrymandering and finished analyzing the extent of gerrymandering in the North Carolina General Assembly. Team members also worked with four local high school students to develop two new algorithms that generate representative collections of redistricting plans, and study how counties must be split to adhere to “one person, one vote” redistricting criteria.

The team saw this research travel all the way to the U.S. Supreme Court. Oral arguments for Common Cause v. Rucho occurred on March 26, 2019; the evidence for this case rested heavily on the expert testimony of Mattingly and the accompanying research, with significant contributions from undergraduates. In addition, the team helped conduct research investigating gerrymandering in the North Carolina legislature, which went into an expert report for Common Cause v. Lewis.


Fall 2018 – Spring 2019  

Team Outputs

Impact of Gerrymandering in America (poster by Gillian Samios, Isaac Nicchitta, Mitra Kiciman, Nima Mohammadi, Rayan Tofique, Yashas Manjunatha, presented at Bass Connections Showcase, Duke University, April 17, 2019)

Gerrymandering in the North Carolina State Legislature (poster by Rahul Ramesh, Jacob Rubin, Haley Sink, Sam Eure, presented at Bass Connections Showcase, Duke University, April 17, 2019)

Detecting a Gerrymander: Sampling the Space of Possible NC Congressional Maps (poster by Luke Farrell, Jacob Shulman, Tiffany Mei, Vinay Kshirsagar, Sam Eure, presented at Bass Connections Showcase, Duke University, April 17, 2019)

Quantifying Gerrymandering (talk by Samuel Eure and Nima Mohammadi, Bass Connections Showcase, Duke University, April 17, 2019)

Project team site


Luke Farrell as a student and an alumnus

This Team in the News

3 Ideas to Reduce Educational Disparities Post-Pandemic

NC Court Upholds New Republican-drawn Congressional Map After Last One Struck Down for Gerrymandering

Democrats Could Pick Up Seats in Congress Under Proposed North Carolina Map

Latest Redistricting Process Led to Much Fairer Maps, Analysis Shows

NC’s Legislative Maps Are Deemed Unconstitutional. So What Does This Mean for 2020?

From a Classroom to the Courts: Team’s Research Cited in Gerrymandering Cases

NC Court Rules State Legislature Maps Unconstitutional, Duke Prof. Weighs In

After Maps Struck Down in NC Gerrymandering Lawsuit, Top Republican Leader Won’t Appeal 

These Seniors Took Their Bass Connections Research Further and Graduated with Distinction

As Court Battles Continue, How Does NC Move Forward With Redistricting?

Kicking Off a Summer of Research With Data+

Class of 2019: Using Math to Fight Gerrymandering

Class of 2019: Eight Students Who Changed Duke...And Themselves

Senior Spotlight: Using Math to Fight Gerrymandering

Supreme Court to Hear North Carolina Gerrymandering Case with Ties to Duke Research

US Supreme Court Hears Gerrymandering Case with Ties to Duke Research

The Supreme Court Takes on Gerrymandering. A Cottage Industry Wants to Prove It's Gone Too Far

All That Hard Work Paid Off’: Duke Students Road-trip to DC to Hear Research They Worked on Cited by Supreme Court

Duke Mathematics Has Its Day in Court

Looking for a Way Forward on Redistricting Reform

Party Lines

Meet the Members of the 2018-19 Student Advisory Council

The Fight against Partisan Gerrymandering Continues

Duke Research Makes Mark on Federal Court Cases over North Carolina Gerrymandering

See related Data+ summer project, Gerrymandering and the Extent of Democracy in America (2018).

Two of the team members at the Supreme Court

Team Leaders

  • Gregory Herschlag, Arts & Sciences-Mathematics
  • Jonathan Mattingly, Arts & Sciences-Mathematics
  • Frederick Mayer, Sanford School of Public Policy

/undergraduate Team Members

  • Isaac Nicchitta, Public Policy Studies (AB)
  • Claire Wiebe, Mathematics (AB)
  • Chris Welland, Mathematics (AB)
  • Ella Van Engen, Mathematics (AB)
  • Rayan Tofique, Computer Science (BS)
  • Haley Sink, Economics (BS)
  • Jacob Shulman, Computer Science (BS)
  • Gillian Samios, Public Policy Studies (AB)
  • Jacob Rubin, Computer Science (BS)
  • Rahul Ramesh, Computer Science (BS)
  • Jay Patel, Computer Science (BS)
  • Nima Mohammadi, Public Policy Studies (AB)
  • Tianxue Mei, Computer Science (BS)
  • Yashas Manjunatha, Computer Science (BS)
  • Vinay Kshirsagar, Computer Science (BS)
  • Mitra Kiciman, Computer Science (BS)
  • Luke Farrell, Interdept Comp Sci/Neuro (BS)
  • Shuyu Fan, Statistical Science (BS)
  • Samuel Eure, Mathematics (BS)

/zcommunity Team Members

  • Andrew Chin, UNC School of Law
  • North Carolinians for Redistricting Reform
  • Common Cause