Read the full brief.

INTEREST OF AMICI CURIAE 

Amici are 27 scholars of election law, scientific evidence, and empirical legal methods at law schools and universities throughout the United States. We have no personal interest in the outcome of this case (except to the extent that it may affect our electoral influence as individual voters), but we have a professional interest in seeing that the law relating to the application of scientific and statistical evidence develops in a way that supports and encourages methodologically sound practices.

SUMMARY OF ARGUMENT 

In enacting the 2016 Plan under the mistaken assumption that “a political gerrymander” was per se legal, the defendants drew at least ten of the Common Cause plaintiffs into districts whose partisan composition was highly atypical of districts drawn in pursuit of legitimate districting objectives. This packing and cracking deliberately muted the normal effects of any actual or potential efforts by these voters to influence election outcomes by switching parties or splitting tickets during the life of the plan. The defendants thereby created a discriminatory arrangement of the electoral system in which each packed or cracked plaintiff’s disfavored partisan affiliation, while mutable in principle, was frozen in practical effect.

Part I of this brief explains how two of plaintiffs’ experts, Jonathan Mattingly and Jowei Chen, applied recent advances in computer technology and the mathematical sciences to demonstrate the atypicality of the plaintiffs’ districts in the 2016 Plan. Mattingly’s and Chen’s analyses of thousands of computer-generated compliant maps showed, inter alia, that the defendants merely complied with their stated legitimate redistricting criteria as constraints and did not pursue them as objectives. In so doing, Mattingly and Chen provided the necessary factual predicates for a judicially manageable framework that does not turn on a finding of excessive or predominant partisan considerations, but on whether the challenged plan was the result of the actual pursuit of legitimate districting objectives. Their analyses also accounted for and excluded each of the alternative explanations for disparate partisan performance that supported this Court’s rejection of the discriminatory effects tests proposed in Bandemer, Vieth, and LULAC. For these reasons, the Panel’s findings of vote dilution as to at least ten of the Common Cause plaintiffs are reliably supported by Mattingly’s and Chen’s analyses and warrant deference.

Part II of this brief explains why the legislative defendants’ mere compliance with legitimate redistricting criteria as constraints cannot immunize their intentional packing and cracking from equal protection liability. Given the ever-increasing effectiveness of computational technology in enabling mapmakers to maximize partisan advantage while maintaining such compliance, traditional districting criteria can meaningfully limit partisan gerrymandering only when the mapmakers actually pursue them as objectives. The defendants relinquished any claim to a safe harbor from equal protection liability when they drew districts that belied any actual pursuit of traditional districting principles and other legitimate legislative criteria as objectives. By using past election results and empirical knowledge of the limited range of cross-election variation at the precinct and VTD level in North Carolina, the defendants engineered district boundaries that would render cross-election voting variations ineffectual in each packed or cracked district for the life of the 2016 Plan, thereby consistently degrading the influence of each packed or cracked plaintiff on the political process as a whole. For these reasons, the Panel’s findings of vote dilution in violation of the Equal Protection Clause as to at least ten of the Common Cause plaintiffs warrant affirmance.