SCOTUS Rules Mathematical Perfection Not Required in Redistricting

In Harris v Arizona Independent Redistricting Commission, 578 U.S. ___ (2016), the U.S. Supreme Court confirmed that although the Fourteenth Amendment’s Equal Protection Clause requires States to attempt to construct legislative districts as nearly of equal population as is practicable, mathematical perfection is not required. The Court went on to find that the deviations, which were less than 10%, predominantly reflected the redistricting commission’s efforts to achieve compliance with the Voting Rights Act.

Facts of Harris v Arizona Independent Redistricting Commission

Following the 2010 census, Arizona’s independent redistricting commission (Commission), which included two Republicans, two Democrats, and one Independent, redrew Arizona’s legislative districts. The Commission received guidance from legal counsel, mapping specialists, a statistician, and a Voting Rights Act specialist.

The initial plan had a maximum population deviation from absolute equality of districts of 4.07%, but the Commission adopted a revised plan with an 8.8% deviation on a 3-to-2 vote, with the Republican members dissenting. After the Department of Justice approved the revised plan as consistent with the Voting Rights Act, appellants filed suit, claiming that the plan’s population variations were inconsistent with the Fourteenth Amendment.

A three-judge Federal District Court sided with the Commission. It held that the “deviations were primarily a result of good-faith efforts to comply with the Voting Rights Act . . . even though partisanship played some role.”

Supreme Court’s Decision in Harris v Arizona Independent Redistricting Commission

The Supreme Court affirmed, concluding that the District Court did not err in upholding Arizona’s redistricting plan. Justice Stephen G. Breyer wrote on behalf of the unanimous Court.

Citing its decision in Reynolds v. Sims, 377 U. S. 533 (1964), the Court noted that the Fourteenth Amendment’s Equal Protection Clause requires States to “make an honest and good faith effort to construct [legislative] districts . . . as nearly of equal population as is practicable.” However, it also emphasized that the Constitution “does not demand mathematical perfection.” In determining what is “practicable,” the Court has held the Constitution permits deviation when it is justified by “legitimate considerations incident to the effectuation of a rational state policy.” The Court listed the following examples: “traditional districting principles such as compactness [and] contiguity;” a state interest in maintaining the integrity of political subdivisions; a competitive balance among political parties; and, before Shelby v. Holder, 570 U. S. ___ (2013), compliance with §5 of the Voting Rights Act.

In reaching its decision, the Court also highlighted that “minor deviations from mathematical equality,” specifically those under 10%, do not, by themselves, “make out a prima facie case of invidious discrimination under the Fourteenth Amendment [requiring] justification by the State.” Here, the Court found that because the deviation was under 10%, the appellants could not rely upon the numbers to show a constitutional violation. Rather, they must show that it is more probable than not that the deviation reflects the predominance of illegitimate reapportionment factors rather than “legitimate considerations.” As Justice Breyer explained:

In sum, in a case like this one, those attacking a state-approved plan must show that it is more probable than not that a deviation of less than 10% reflects the predominance of illegitimate reapportionment factors rather than the “legitimate considerations” to which we have referred in Reynolds and later cases. Given the inherent difficulty of measuring and comparing factors that may legitimately account for small deviations from strict mathematical equality, we believe that attacks on deviations under 10% will succeed only rarely, in unusual cases.

The Court went on to hold that the appellants had failed to meet their burden. According to the justices, the record supported the District Court’s conclusion that the deviations predominantly reflected Commission efforts to achieve compliance with the Voting Rights Act, not to secure political advantage for the Democratic Party.

Finally, the Court concluded that because it decided Shelby County v. Holder after Arizona’s plan was created, it has no bearing on the issue whether the State’s attempt to comply with the Voting Rights Act is a legitimate state interest.