Partisan symmetry
From Ballotpedia
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redistricting procedures |
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2020 |
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In redistricting, partisan symmetry is the principle that a particular share of the total votes received by a party should translate into a specific number of legislative seats, regardless of which party received that share of the total votes. Consider the following example:[1][2]
- Example: In hypothetical State A, there are 20 congressional seats. In the last election, Party A won 60 percent of all votes cast in congressional elections and 80 percent of the total number of congressional seats (i.e., 16 seats). The partisan symmetry standard would be met if one could prove that Party B would have also won 16 seats if it had won 60 percent of all votes cast. If, however, one could prove that Party B would have fewer seats after winning the same share of all votes cast, this would indicate a breach of the partisan symmetry principle in favor of Party A. This dissymmetry could result from either packing or cracking the voting blocs that support Party B, thereby diluting their influence.
Partisan symmetry itself is not a measure but rather a standard for defining partisan gerrymandering. Various metrics, including the efficiency gap, have been proposed as a means of determining whether a district map meets the partisan symmetry principle.[3]
See also
External links
- All About Redistricting
- National Conference of State Legislatures, "Redistricting Process"
- FairVote, "Redistricting"
Footnotes
- ↑ The Washington Post, "We have a standard for judging partisan gerrymandering. The Supreme Court should use it." February 2, 2017
- ↑ Election Law Journal, "The Future of Partisan Symmetry as a Judicial Test for Partisan Gerrymandering after LULAC v. Perry," Volume 6, Number 1, 2007
- ↑ University of Chicago Law Review, "Partisan Gerrymandering and the Efficiency Gap," Spring 2015
