Redistricting and Gerrymandering: Current State of Play

Transcription

1 Redistricting and Gerrymandering: Current State of Pay Matthew Satzman Cemson University Mathematica Sciences LWV of the Cemson Area LWVSC LEAD January 27, 2018

2 My Introduction to the Subject

3 What Are Redistricting and Gerrymandering? Redistricting is the decennia process of redrawing congressiona and egisative district boundaries Gerrymandering is drawing the ines in a way that infuences the outcomes of eections

4 Types of Gerrymandering Racia Prohibited by Voting Rights Act (1965) Discriminatory effect Group sufficienty arge and compact? Minority votes in a boc? Majority boc votes against minority? Partisan Under review by Supreme Court Nonpartisan Protects incumbents regardess of party

5 What Gerrymandering Is Not "A gerrymander is by definition and common understanding, a strange ooking monster drawing. This map is ceary not that." Robin Hayes, NC Repubican Party Chair (10- Jan-2018) NC-2 and NC-4 Some sort of ogre eating a squirre.

6 Genera Principes For Districts Equa popuations One person, one vote (Reynods v. Sims, 1964) Contiguous and compact (whatever that means) Shoud not break up communities of interest Respect existing poitica boundaries (municipaities, counties) Must not unduy disadvantage minority voters Voting Rights Act of 1965

7 Compact?

8 Measuring Compactness Compare district area to some idea area Gives a number between zero and one Posby-Popper A = area, P = perimeter, then 4πA/P 2 Ratio of area to area of a circe with same perimeter Reock score Smaest encosing circe Convex hu Smooth out a indentations ( rubber band encosure ) Different measures score the same shape differenty

9 Compactness In Pictures Convex Hu Posby-Popper Reock

10 Other Issues With Shape What is perimeter? Coastine paradox What are unbreakabe units? Census bocks, bock groups, tracts Spit precincts Shape vs. other criteria Communities of interest Minority or party distribution

11 How To Gerrymander Cracking Spitting communities among severa districts to ensure that they don t constitute a majority in any of them Packing Concentrating communities into a few districts where they win overwhemingy, but not enough seats to have infuence in the egisature

12 How To Gerrymander

13 How To Gerrymander

14 Cracking: What s Going On Here? NC11-NC12 Ashevie Gerrymander 5K Route

15 How To Measure Partisan Gerrymandering Extent Efficiency of a vote A vote is considered wasted if it is A vote for the osing candidate A vote for the winning candidate over the minimum needed to win (50% + 1 vote) Efficiency Gap Tota of osing party s wasted votes minus tota of winning party s wasted votes, divided by tota votes A rough guide Fraction of osing party seats compared to fraction of osing party votes

16 Efficiency Gap Exampe Five equa-sized districts Democrats win two, 76% to 24% Repubicans win three, 59% to 41% Democrats waste 26% in each win, 41% in each oss Repubicans waste 9% in each win, 24% in each oss Efficiency gap ( )/5 = 20% in favor of Repubicans Democrats receive 55% of the vote but win ony 40% of seats

17 How Extreme Is An Outcome? Simuation Draw ots of nonpartisan maps Check outcomes using precinct resuts Test ikeihood of outcomes at east as extreme as actua An unikey outcome is evidence of gerrymandering

18 When Is The Gap Too Big? Technica evidence Significant increase over past eections Significanty more than other ocations Significanty more than other possibe maps (simuation) Insensitive to pausibe shifts in voter preferences Lega evidence Intent to discriminate Effect is discriminatory Other possibe expanations Natura custering of Democrats in urban areas Wi need to buid case aw

19 Partisan Gerrymandering: Reevant Lega Cases Constitutiona grounds First Amendment (freedom of association) Fourteenth Amendment (equa protection) Vieth v. Jubeirer (2004) Justice Kennedy: Partisan gerrymandering coud be justiciabe if standards coud be deveoped to identify it

20 Partisan Gerrymandering: Reevant Lega Cases Gi v. Whitford (2017, Wisconsin) Repubicans accused of poitica gerrymandering Paintiff s argument based on efficiency gap District Court found for paintiff Heard at Supreme Court, 3-Oct-2017 Socioogica gobbedegook Chief Justice Roberts What becomes of the precious right to vote? Justice Ginsburg

21 Partisan Gerrymandering: Reevant Lega Cases Benisek v. Lamone (2018, Maryand) Democrats accused of poitca gerrymandering District Court found for defendants Ony one district invoved To be heard in Supreme Court (no date set)

22 Partisan Gerrymandering: Reevant Lega Cases LWVNC v. Rucho (2018, North Caroina) District Court struck down current map as unconstitutiona gerrymander by Repubican-controed egisature Ordered maps redrawn by 24-Jan-2018 Supreme Court issued stay unti appea Paintiffs have requested expedited review

23 Partisan Gerrymandering: Reevant Lega Cases LWVPA v. Commonweath of Pennsyvania (2018) Repubicans accused of poitica gerrymandering The gerrymander of the decade. Sean Trende (RCP) State Supreme Court rues that district ines vioate state constitution New maps ordered by 9-Feb-2018 Appea to Supreme Court not yet resoved

24 Action Items LWVSC supports South Caroina House bi H.4456 and Senate bi S.341 Nonpartisan commission, nonpartisan and non-sweetheart standards Contact your state egisators! 2020 census is in danger Underfunding, partisan director, citizenship question Contact your federa egisators!