Table Of ContentMake redistricting great again
A comparative study of the decennial
congressional redistricting process and
partisan bias from 2012-2016
Vilde Marie Ørnung
Master thesis at the Department of Political Science
Faculty of Social Sciences
UNIVERSITY OF OSLO
30.04.2018
Word count: 33 009
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Make redistricting great again
A comparative study of the decennial congressional redistricting process and partisan bias in
the U.S. House of Representatives elections from 2012-2016
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© Vilde Marie Ørnung
2018
Make redistricting great again
Vilde Marie Ørnung
http://www.duo.uio.no/
Trykk: Allkopi, Parkveien
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Abstract
This thesis is a comparative study of the congressional redistricting process in 43 states and
an analysis on partisan bias in the U.S. House of Representatives elections in 2012, 2014 and
2016. Partisan bias is, generally speaking, bias beneficial to one party in the translation of
votes to seats in an election. The analysis is based on secondary analysis of both qualitative
and quantitative data. The renowned metrics of the efficiency gap and partisan symmetry is
used to measure partisan bias. The study has shown that politicians in a majority of states
redraws congressional district lines every ten years contrary to using independent
commissions to draw the lines. In 2011, the Republican Party drew voting districts in 17
states and some of these states have among the highest bias measured in all three elections
after redistricting. In the literature, there is some disagreement on what is causing this bias;
partisan gerrymandering or self-sorting of voters, or both. In 2018, the United States Supreme
Court will decide whether partisan gerrymandering is constitutional, and thereby affecting the
redistricting process and possibly influencing the ability of voters to choose their leaders.
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Acknowledgements
The process of writing this thesis has been, to use a cliché, a rollercoaster in many ways.
Never have I been more frustrated or worked harder on anything. It has been challenging, but
also so much fun to write about something that has really interested me ever since I saw the
first episodes of the West Wing in high school. I am glad I listen to my heart when deciding
on the subject for this master thesis.
I want to thank my thesis advisor, Professor Bjørn Erik Rasch, for all the inputs and advice he
has given me throughout the last months of this project. I also want to thank Professor
Anthony McGann for providing me with calculations on partisan symmetry.
My mother deserves a big hug and appreciation for always listening to my concerns and
giving me encouragement. I do not think I would have finished without your help!
Thank you to my father who always believed in me even when I did not believe in myself. I
miss you.
Thank you to Siri who was so kind to read my thesis and give me feedback in the last weeks
before the deadline.
A stressful few months would have been so much more challenging without the company of
Marianne and Ida at Blindern.
All the errors in this thesis are my own.
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Table of contents
1 Introduction ...................................................................................................................... 1
1.1 Research question ........................................................................................................ 2
1.2 Limitations ................................................................................................................... 5
1.3 Methodology ................................................................................................................ 5
1.4 Data .............................................................................................................................. 6
1.5 Theory and concepts .................................................................................................... 6
1.6 Structure of thesis ........................................................................................................ 7
2 Elections in single-member districts in a federal system, geographical bias, and
gerrymandering ........................................................................................................................ 9
2.1 The political system in the United States .................................................................. 10
2.1.1 Federalism .......................................................................................................... 10
2.1.2 Plurality rule in single-member districts ............................................................ 12
2.1.3 Two-party system ............................................................................................... 12
2.2 Voting and population distribution ............................................................................ 14
2.2.1 Majority-minority district as a source of geographical bias ............................... 17
2.3 Gerrymandering: intentional manipulation of voting districts .................................. 18
2.3.1 Partisan gerrymandering .................................................................................... 21
2.4 Closing remarks ......................................................................................................... 25
3 Redistricting .................................................................................................................... 26
3.1 What is redistricting? ................................................................................................. 26
3.1.1 Apportionment ................................................................................................... 26
3.2 Requirements and limitations of the congressional redistricting process .................. 27
3.2.1 Federal requirements .......................................................................................... 27
3.2.2 State-based requirements .................................................................................... 29
3.3 2010 Census ............................................................................................................... 31
3.4 Redistricting in 2011 ................................................................................................. 32
3.5 Closing remarks ......................................................................................................... 33
4 State-by-state redistricting procedures ........................................................................ 34
4.1 Categorization ............................................................................................................ 34
4.1.1 Legislative-based redistricting ........................................................................... 36
4.1.2 Commission-based redistricting ......................................................................... 40
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4.2 Closing remarks ......................................................................................................... 43
5 Methodology ................................................................................................................... 44
5.1 Timeframe ................................................................................................................. 44
5.2 Research design ......................................................................................................... 45
5.2.1 Comparative methods ......................................................................................... 45
5.3 Data ............................................................................................................................ 47
5.3.1 Critique of sources ............................................................................................. 47
5.4 Selection of cases ....................................................................................................... 48
5.4.1 Mahoney and Goertz’ Possibility Principle ....................................................... 48
5.5 Tables and categorization .......................................................................................... 50
5.6 Closing remarks ......................................................................................................... 53
6 How to measure partisan bias ....................................................................................... 54
6.1 The efficiency gap ..................................................................................................... 54
6.1.1 How to measure the efficiency gap .................................................................... 55
6.1.2 Critique and limitations of the measurement ..................................................... 56
6.2 Gelman and King’s partisan symmetry standard ....................................................... 58
6.2.1 The logic of partisan symmetry .......................................................................... 58
6.2.2 Critique and limitations of the measurement ..................................................... 60
6.3 Other measures of partisan bias ................................................................................. 61
6.3.1 The Polsby-Popper Test ..................................................................................... 61
6.4 Validity ...................................................................................................................... 61
6.5 Reliability .................................................................................................................. 63
6.6 Closing remarks ......................................................................................................... 64
7 Partisan bias during the last decade ............................................................................. 66
7.1 The efficiency gap ..................................................................................................... 67
7.2 Partisan symmetry ..................................................................................................... 74
7.3 Comparing the partisan symmetry standard to the efficiency gap ............................ 77
7.4 Polsby-Popper Index.................................................................................................. 78
7.5 Closing remarks ......................................................................................................... 79
8 Republican bias in Republican-drawn states............................................................... 81
8.1 Motives and opportunities to gerrymander ................................................................ 82
8.1.1 Why increasing polarization can contribute to gerrymandering and high bias .. 82
8.2 The disappearing bias ................................................................................................ 83
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Description:Gerrymandering: intentional manipulation of voting districts . uncertainty when making inferences from congressional districts using this threshold.
