Session 2 – Project Overview CSE 416, Section 1 Semester Project Discussion Session Objectives � Understand issues and terminology used in US congressional redistricting and voting analysis � Understand data requirements to support voting analysis � Become familiar with gerrymandering and techniques to measure the relative amount of gerrymandering in a state district plan � Understand issues associated with currently available data We will explore the project functionality in more detail in the next 1-3 class sessions 2 � Robert Kelly, 2020 1 9/24/2020 � Robert Kelly, 2020
Session 2 – Project Overview Teams � You should form your team soon (4 members) � You can register a 3-member team, but I will likely add a 4 th member You register your team by You should use Piazza to sending me an email message look for possible students in with the names of the team your team members 3 � Robert Kelly, 2020 Project Background � Project based on � Fall 2017 CSE308 – apply quantitative measures of political gerrymandering � Fall 2018 CSE308 – explore feasibility of algorithms for the generation of districts � Spring 2019 – explore feasibility of integrating demographic data � Fall 2019 – analyze demographic voting patterns Underlying issue is the � Lessons learned from previous projects question of racial fairness in US elections � Robust set of data available � Graph algorithms for the generation of viable congressional districts 4 � Robert Kelly, 2020 2 9/24/2020 � Robert Kelly, 2020
Session 2 – Project Overview Why This is an Important and Interesting Topic � Very current � Lots of interesting CS concepts and technologies � Multiple languages � Multiple computers � Database � algorithms � Realistic software development project 5 � Robert Kelly, 2020 Background Info � Every state has a number of Population in districts congressional districts proportional to the state population must be almost equal � Population is recalculated after a US Census, and district boundaries must be recalculated if the number of representatives change or population shifts � District boundaries can also change due to court decisions (e.g., Pennsylvania, North Carolina, etc.) Most states will be redistricted following the 2020 census US Census is performed every 10 years 6 � Robert Kelly, 2020 3 9/24/2020 � Robert Kelly, 2020
Session 2 – Project Overview Precincts (sometimes known as Wards) � Lowest level government division � Contained in one polling place � Data usually available for voting totals 7 System Background � Current redistricting approach leads to many unfair practices (Gerrymandering) � Some US states have a history of denying equal voting to some minority groups (e.g., African American) � Recent approaches involve “packing” minorities into a small number of districts, thereby minimizing their overall representation "I propose that we draw the maps to give a partisan advantage to 10 Republicans and three Democrats because I do not believe it’s possible to draw a map with 11 Republicans and two Democrats.“ – Chairman of NC House redistricting committee 8 � Robert Kelly, 2020 4 9/24/2020 � Robert Kelly, 2020
Session 2 – Project Overview What is a Gerrymander? � Refers to a voting district that resembles a salamander � Named after Eldridge Gerry, 5 th VP of US 9 � Robert Kelly, 2020 Why is Gerrymandering a Hot Topic? � Gerrymandering is a practice intended to establish an advantage for a particular party or group by manipulating district boundaries � Usually features “cracking” (split opposing party voters into many districts and “packing” (packing maximum number of opposing party voters in to a handful of districts) � Occurring in the US since 1812 � Used aggressively in 2010, resulting in congressional dysfunction Definition from Wikipedia 10 � Robert Kelly, 2020 5 9/24/2020 � Robert Kelly, 2020
Session 2 – Project Overview Consequences of Current Gerrymandering � Many congressional seats are not competitive � Members of congress are more concerned with a primary battle than an election battle � Republicans and Democrats represent their party’s position more than the wishes of their constituents � Extremes of each party dominate, instead of the middle Congressional Gridlock 11 � Robert Kelly, 2020 1965 Voting Rights Act � VRA � Forced selected states to obtain pre- clearance for any election change that might affect the right to vote in a state � Was very effective in restoring voting rights in the pre-clearance states � 2013 decision of Supreme Court struck down parts (e.g., preclearance) of the VRA � Majority-minority provisions remain, which has been used to enable district packing of congressional districts 12 � Robert Kelly, 2020 6 9/24/2020 � Robert Kelly, 2020
Session 2 – Project Overview Minority Packing � Congressional redistricting in many states is controlled by one political party � The party in power tries to preserve its power by drawing voting districts that favor the party � Data is now available that show the voting preferences and racial/ethnic characteristics of individual geographic locations � Redistricting groups attempt to “pack” opposition voters (70%-80%) into a small number of districts while “cracking” the remaining opposition voters (40%-45%) into the remaining districts 13 � Robert Kelly, 2020 Congressional District Observations � Many districts appear oddly shaped, possibly due to attempts to pack minority groups � Recent measurements of gerrymandering, but not including racial/ethnic origins � New probabilistic approach to measuring gerrymandering developed at Duke University � MGGG applied a probabilistic approach to Virginia state legislature districting to measure racial gerrymandering � Probabilistic measures limited by computational requirement 14 � Robert Kelly, 2020 7 9/24/2020 � Robert Kelly, 2020
Session 2 – Project Overview Fall 2020 Project � Apply a modified version of the Duke and MGGG for a large number of states � Measure the extent to which current districting plans appear to be biased in terms of racial/ethnic distribution of population in congressional districts � Consider legal effects of packing in analysis (e.g., urban vs. rural) � Consider impact of VRA on packing effects Computation of this analysis requires an interesting combination of programming (multi-processors), computer science (e.g., graph algorithms), and applied math 15 � Robert Kelly, 2020 High Level View of the Project � Build a robust system to � Display a current districting plan for a state � Generate a “random” set of districting plans for the state � Calculate the racial/ethnic population in each random district � Generate the racial/ethnic population distribution � Determine if the current districting plan does not appear fair � Generate a large number of districting plans on a high performance computer � Display graphic results to the user 16 � Robert Kelly, 2020 8 9/24/2020 � Robert Kelly, 2020
Session 2 – Project Overview Generating a “Random” District � Goal - Allow congressional district boundaries to be automatically determined in a “random” way � Approach � Treat precincts as nodes in a graph � Edges in the graph are defined by contiguity (200+ foot shared border) � Partition the statewide precinct graph into the set of connected sub- graphs � Rebalance the sub-graphs to satisfy state districting constraints (e.g., equal population, compactness) 17 � Robert Kelly, 2020 System Display � Districts and precinct boundaries are displayed � The characteristics of a large number of random districting plans are displayed � Setup of a run defines the constraints in districting (e.g., compactness) Data is available from multiple data sources 18 � Robert Kelly, 2020 9 9/24/2020 � Robert Kelly, 2020
Session 2 – Project Overview Project Requirements Analysis � You will generate detailed requirements (use cases) � Requirements will evolve over the first 6 weeks of the project � Top-Level functional requirements provided in first 2 weeks of class sessions � You will develop detailed requirements based on top-level requirements � Team requirements aggregated into a master use-case list � Near-final set of use cases by early October 19 � Robert Kelly, 2020 Ethnic Minority Data � Ethnic minority data should be included in your precinct data � 1965 Voting Rights Act mandates the establishment of districts in which an ethnic minority constitutes a majority within the district Each precinct includes demographic data originated from the US Census Bureau 20 � Robert Kelly, 2020 10 9/24/2020 � Robert Kelly, 2020
Session 2 – Project Overview VRA Preclearance States � Alabama � Alaska � Arizona Your team will choose 3 � Georgia states to analyze, and at least one of them will be a � Louisiana pre-clearance state � Mississippi � South Carolina � Texas � Virginia 21 � Robert Kelly, 2020 What Data is Needed? � Geospatial boundary data A data repository will be made � Precincts available to you that will contain � Existing Congressional districts some of the data you need � Cities/counties � Census tracts (including demographic data) � Election results data Multiple data sources can be used to measure the party preference of a precinct (congressional vote, presidential vote, registration, etc.) 22 � Robert Kelly, 2020 11 9/24/2020 � Robert Kelly, 2020
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