Redistricting Glossary
Community of interest – a contiguous population which shares common social and economic interests that should be included within a single district for purposes of its effective and fair representation.
Compactness – districts which are not spread out or too jagged.
Contiguity – all areas in the district are physically connected to each other.
Cracking – a method of diluting a minority community’s voting power by splitting the minority community into two or more districts so that the minority community does not constitute a significant portion of any district. For example, cracking occurs when a racial minority population is big enough that it can make up 50% of one district but, instead, is divided into two or more districts so that the minority community makes up a small percentage in each district.
Minority vote dilution – diluting a racial minorities vote. The most common forms are (1) packing and (2) cracking.
Packing – a method of diluting a community’s voting power by concentrating a minority population into a suboptimal number of districts. For example, packing occurs when a racial minority population makes up 90% of the district instead of two districts where the minority population could make up 50% of each district.
Population equality – a requirement that political districts (such as state legislative districts) have a “reasonably equal” number of residents.
Voting Rights Act (VRA) – a federal civil rights law that prohibits discriminatory voting practices. The VRA contains various sections. Section 2 of the VRA protects against racial minority vote dilution where (1) a racial minority is big enough to make up a majority in one district, (2) the minority group is politically cohesive, and (3) the majority votes as a bloc to consistently defeat the minority group’s preferred candidate.
Glossary credit: (http://www.capafr.org/redistricting-basics)

