The Princeton Gerrymandering Project does nonpartisan analysis to understand and eliminate partisan gerrymandering at a state-by-state level.

The Supreme Court acknowledged the validity of our math but declined to act. Looking ahead, the strongest route to reform is at a state-by-state level — a federalist approach.

Our interdisciplinary team aims to give activists and legislators the tools they need to detect offenses and craft bulletproof, bipartisan reform. Our analysis is published widely, and our work is used by legislators and reformers of all communities, without regard to partisan affiliation.

We translate math into law, and law into math.

Election laws and the Constitution are silent on critical issues of representation and districting. By understanding the real-world impacts of the law as it stands, we can help patch holes and fix bugs. Despite a recalcitrant Supreme Court, paths to reform remain open in federal courts, state courts, state ballot initiatives, and state legislation. In a recent paper, we describe an interdisciplinary approach where mapmaking, statistics, and law can work together to fill a current legal void.

We provide rigorous standards to constrain bad acts.

We develop and use mathematical tests that rigorously diagnose unequal opportunity and unfair outcomes in district maps. For instance, we lay out three statistical tests for gerrymandering in the Stanford Law Review, the results of which can be seen on the tests page. They are applicable in claims against individual districts and in claims against statewide districting schemes. These claims can be brought in federal and state courts under different legal provisions, not all of which are subject to review at the U.S. Supreme Court. We are also developing methods for determining whether individuals’ votes are diluted in violation of Equal Protection.

We help activists and lawmakers.

The Princeton Gerrymandering Project supports state- and federal-level reform efforts to eliminate partisan gerrymandering. We identify opportunities and loopholes in existing law that shape how district maps are drawn. We can help analyze and craft reform language to help activists translate their ideals into practical solutions. We have produced projects and reports for reformers in Virginia and Michigan, with the goal of advancing redistricting reform in those states. In December 2018, we also drew attention to weaknesses in a redistricting reform bill proposed by New Jersey lawmakers and testified about our findings in committee hearings.

We level the redistricting playing field.

To harness the power of data, we are building OpenPrecincts, which we hope will be the nation’s most accurate and comprehensive database for redistricting. OpenPrecincts will be a collaborative open-source database housing election precinct geographies for all 50 states, the District of Columbia, and Puerto Rico. By providing data to free online redistricting programs, OpenPrecincts will empower citizens with the tools necessary to have a meaningful say in the 2021 redistricting process. Stay tuned for more!


State Reports

We will prepare reports that include demonstration maps, as well as statistical and legal analyses to help good-government groups craft lasting reform strategies.

Improved Communication

We will show statisticians how to advance reform, activists how to write foolproof laws, and lawyers how to create arguments backed by mathematical rigor.


Currently, there is no central repository of precinct-level geographic data from across the country available to the public. This data has to be collected from thousands of counties nationwide. We will provide this data to the public, through a combination of our own data-gathering and data-cleaning efforts, as well as coordinating the activities of civic technologists nationwide. The information will be provided to the public through portals that will allow them to use the data to evaluate plans and to draw their own maps.


The Princeton Gerrymandering Project is supported by Educational Ventures, Schmidt Futures, the Marilyn J. Simons Foundation, and other private donations.