Princeton Election Consortium

Wesley Pegden of Carnegie-Mellon University, Jonathan Rodden of Stanford University, and I joined forces on an amicus brief (PDF). We offered the court our views on the federal partisan gerrymandering case from North Carolina, Rucho v. Common Cause (this link goes to all the other briefs as well). We describe to the court how the various tests of partisan unfairness fall into two big categories: inequality of opportunity and inequity of outcome. We furthermore describe how the drawing of many alternative maps can do both jobs.

Wesley Pegden is best known in redistricting circles for a theorem he and co-authors published last year regarding the Monte Carlo Markov chain approach. This approach finds many (typically billions) of maps that are made by making small changes to a candidate map. He showed that if the candidate map is most extreme of N such maps, it must be in the O(1/sqrt(N)) range of maps that can be reached by MCMC. He, Moon Duchin, and Jonathan Mattingly (expert in the N.C. case) have all been applying this approach to redistricting with great effectiveness.

Jonathan Rodden has a long history of drawing ensembles of maps. Using older methods, he and Jowei Chen (now at University of Michigan) have used a random-seeding approach to draw hundreds of maps, not related to one another, to explore a wide range of possibilities.

My own contribution to this brief was to point out that despite the proliferation of map-based and simpler numerical-measurement tests, they fall into two big buckets from a legal standpoint: inequality of opportunity and inequity of outcome. That was the subject of our recent prizewinning entry in the Common Cause contest. Examples include lopsided wins (test of opportunity; applies to N.C.) or uniform wins (again a test opportunity; applies to Maryland). MCMC tests both opportunity and outcome.

We were very ably represented by Tacy Flint. She is a former clerk of Richard Posner and of Stephen Breyer, and she led a legal team at Sidley Austin. All in all, it was a dream team of co-authors and counsel. It was a pleasure to work together!

Uncertain about whether the Supreme Court will do anything about partisan gerrymandering? We have something for you. Rick Ober, Ben Williams, and I have completed a manuscript, “Laboratories of Democracy Reform: State Constitutions and Partisan Gerrymandering.” It’s available here on SSRN.

In our article, we argue that partisan gerrymandering can be curtailed on a local basis using state law and constitutions. The intellectual framework was laid out by Chief Justice John Roberts and Justice Elena Kagan in their decision and concurrence in Gill v. Whitford. And even if they themselves don’t use it, this framework is available for state courts to use under state law.

Their logic is built upon the concepts of equal protection and freedom of association: voters should not be penalized individually (Roberts; equal protection) or in the aggregate (Kagan; freedom of association) for expressing partisan views. As it happens, these provisions are found in state constitutions across the nation.

So long as it doesn’t conflict with federal law, a state court-based ruling is not subject to review in federal court. And generally, it is possible for state courts to provide for more rights than federal courts do. So a new state protection can be reconciled with a wide range of possible actions by the Supreme Court on the North Carolina and Maryland cases currently before it. We give dozens of examples where states used their own law or constitution to overturn a map. Finally, we suggest states where conditions may be right for a local approach, including North Carolina and Wisconsin.

Unleash your inner Federalist!