Do Redistricting Commissions Avoid Partisan Gerrymanders?

Abstract

As attempts to combat partisan gerrymandering transition from proposals to the Supreme Court to state-based districting commissions, it is time to ask two questions. First, how well did commissions in the 2010 round of redistricting perform as neutral decision makers? We answer that question with applications to each of the three independent commissions (AZ, CA, and WA) and four other commission forms (IA, NJ, NY, and VA) in place for post-2010. We take as the neutrality criterion the idea that a commission would produce a district plan that comports with a partisan outcome that could be expected from a set of approximately 10,000 computer generated plans adhering to minimalist constraints of contiguity, compactness, and equal populations. Our results indicate three of seven commissions produced suspect results that redounded to the benefit of one party or the other: pro- Democrat in Arizona; pro-Republican in New Jersey and Virginia.

A Partisan Solution to Partisan Gerrymandering: The Define–Combine Procedure

“…Independent commissions should insulate the redistricting process from the most extreme maps sought by partisans; however, political scientists have not yet reached a full consensus on the success of independent commissions. On the one hand, some recent research has found that independent commissions in the 2020 redistricting cycle tended to produce maps with less partisan bias (Best et al 2022;Kenny et al 2023;Warshaw et al 2022); on the other hand, other work has argued that the effectiveness of commissions can be undermined by partisan members of a commission and by tiebreaking procedures that typically benefit one party over the other, reducing incentives for bipartisan mapmaking (Brennan Center for Justice 2018;McDonald 2004;Miller and Grofman 2013).…”