SPATIAL CONSTRAINTS ON GERRYMANDERING : A PRACTICAL COMPARISON OF METHODS

In the half-century since the US Supreme Court asserted its dominion over legislative districting, it has recognized the harm of political gerrymandering but failed to provide relief for it. An earlier, extended period of successful Congressional action suggests reviving the legislative remedy. Historically, Congress required equipopulous, contiguous, and compact districts, but the formal definition of compactness has proven contentious. Does it matter? This paper presents a credible, quantitative framework for evaluating the implications of spatial constraints in districting reform. By implementing a flexible automated districting procedure with eighteen different definitions of compactness, I evaluate their practical implications: the seat shares that they imply for the two parties and for racial and ethnic minorities. On these grounds, the definitions are markedly consistent. The choice among compactness definitions need not be contentious. Political gerrymandering, the manipulation of the borders of legislative districts for partisan gain, affects party representation and reduces voter confidence in government. The United States will next redistrict in 2020-2022 after the 24th Census, and gerrymandering stands as a fulcrum in the balance of national political power. Despite a pervasive focus in this domain on the courts, judicial intervention appears unlikely. It has been half a century since the “Reapportionment Revolution” when the Supreme Court assumed responsibility for enforcing the equipopulation of legislative districts. Three decades have passed since the Court ruled in Davis v. Bandemer (478 U.S. 109, 1986) that political gerrymandering is a justiciable harm. But the Court has failed in that time to identify a “clear and manageable standard” or a “limited and precise rationale” for recognizing gerrymandering, and has declined to provide relief. (Vieth v. Jubelirer , 541 U.S. 267, 2004) In the 2017-2018 term, the Court again demurred with Gill v. Whitford, Benisek v. Lamone, and Rucho v. Common Cause; with an increasingly conservative bench, future action appears unlikely. Historically and constitutionally, Federal districting reform is the purview of Congress. This paper aims to reinvigorate debate over the legislative remedy. The Constitution gives Congress powers over the “Times, Places and Manners of holding Elections. ” (Article 1, §4) Congress has exercised these powers to regulate the constituencies of the House of Representatives, and continues to do so. With the Apportionment Act of 1842, Congress required that states elect members from contiguous, single-member districts. (Cong. Globe, 1842) In 1872, Congress stipulated further that the districts be equipopulous. (17 Stat. 28, 1872) And from 1901 to 1929, districts were to be “composed of contiguous and compact territory and containing as nearly as practical an equal number of inhabitants. ” (31 Stat. 733, 1901) In the immediate aftermath of the Reapportionment Revolution, both houses revived those requirements in 1967 only for the bill to fail in conference. (Cong. Quarterly, 1968) Federal law today requires E-mail address: jsaxon@uchicago.edu. Date: November 21, 2018. The disagreement arose not over the requirements of compactness or contiguity, but over the level of population equality to be required before the 1970 Census, and the time alotted to states for redistricting in the interim. In the Senate version, the time alotted to the states was as low as three months. By 1967, the 1960 Census was quite dated. A new Census was impracticable, and there were concerns that strict rules and a tight clock would 1