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Assessing California’s Redistricting Commission – Briefing Slides

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object(Timber\Post)#3742 (44) { ["ImageClass"]=> string(12) "Timber\Image" ["PostClass"]=> string(11) "Timber\Post" ["TermClass"]=> string(11) "Timber\Term" ["object_type"]=> string(4) "post" ["custom"]=> array(5) { ["_wp_attached_file"]=> string(44) "eventbriefing_assessingredistricting0318.pdf" ["wpmf_size"]=> string(7) "1049136" ["wpmf_filetype"]=> string(3) "pdf" ["wpmf_order"]=> string(1) "0" ["searchwp_content"]=> string(4666) "Assessing California’s Redistricting Commission Effects on Partisan Fairness and Competitiveness March 2018 Eric McGhee Outline  Background and context  Commission plans: fairness  Commission plans: competitiveness  Conclusions and recommendations 2 Citizen Redistricting Commission (CRC) was a big change  Elected state legislature  independent appointed commission  Some constraints  specific criteria  A few public hearings  dozens of public hearings, internet streaming, explanatory report  Any partisan coalition  partisan membership and coalition dictated by law 3 Fair and competitive plans hoped for but not required  Fairness: neither party gets too many seats given its vote  Competitiveness: many seats change hands as vote changes  But law only required: – No party favorites – No incumbent favorites 4 Outline  Background and context  Commission plans: fairness  Commission plans: competitiveness  Conclusions and recommendations 5 How do gerrymanders work? 50 VOTERS 20 BLUE 30 RED 6 How do gerrymanders work? 5 DISTRICTS 3 BLUE 2 RED 7 The packed districts 9 RED - 1 BLUE 8 The packed districts “LOST” VOTES 9 RED - 1 BLUE 9 The packed districts “LOST” VOTES + “SURPLUS” VOTES 9 RED - 1 BLUE 10 The cracked districts 4 RED – 6 BLUE 11 The cracked districts 4 RED – 6 BLUE “LOST” VOTES 12 The cracked districts 4 RED – 6 BLUE “LOST” VOTES + “SURPLUS” VOTES 13 The efficiency gap compares wasted votes SURPLUS VOTES + LOST VOTES SURPLUS VOTES + LOST VOTES TOTAL VOTES X 100 14 The efficiency gap compares wasted votes 8 + LOST VOTES SURPLUS VOTES + LOST VOTES TOTAL VOTES X 100 15 The efficiency gap compares wasted votes 8 SURPLUS VOTES ++ 12 LOST VOTES X 100 TOTAL VOTES 16 The efficiency gap compares wasted votes 3 20 + LOST VOTES TOTAL VOTES X 100 17 The efficiency gap compares wasted votes 20 TOTAL VOTES 3 + 2 X 100 18 The efficiency gap compares wasted votes 20 5 X 100 50 19 The efficiency gap compares wasted votes 15 X 100 50 20 The efficiency gap compares wasted votes +30% 15 X 100 50 21 The efficiency gap can be either seats or seat share  Seat share = seat advantage relative to potential advantage – 30%  Seats = total seat advantage – 30% of 5 = 1.5 22 The efficiency gap can be either seats or seat share  State legislatures  seat share – Power = seat advantage relative to potential advantage  Congress  sometimes seat share, sometimes seats – One seat always means the same thing for congressional majority BUT – Large states can have bigger seat gaps by accident 23 How does the CRC’s efficiency gap look?  CRC vs. state legislature  California vs. other states 24 Assembly CRC plan is fair, with little change 25 Senate CRC plan is fair, with slightly more change 26 Congressional CRC plan has big raw seats change… 27 …but seat share change is small 28 Efficiency gap trends vary over time 29 Efficiency gap trends vary over time 30 Efficiency gap trends vary over time This slide was corrected after the event. 31 Outline  Background and context  Commission plans: fairness  Commission plans: competitiveness  Conclusions and recommendations 32 What does “competitive” mean?  Districts with vote share outcomes between 45% and 55%  CRC vs. state legislature  California vs. other states 33 Assembly CRC plan is much more competitive, but still on low end nationally 34 Senate CRC plan is somewhat more competitive, but still on low end 35 Congressional CRC plan is much more competitive, and on high end 36 CRC plans are consistently more competitive 37 CRC plans are consistently more competitive 38 CRC plans are consistently more competitive 39 Outline  Background and context  Commission plans: fairness  Commission plans: competitiveness  Conclusions and recommendations 40 Conclusions  CRC plans are as fair as previous plans – But with greater tilt toward Democrats  CRC plans are more competitive than previous plans – But still tend to be uncompetitive 41 Recommendations  Use all information  Pick goals in advance  Use computer-simulated maps 42 Assessing California’s Redistricting Commission Effects on Partisan Fairness and Competitiveness March 2018 Eric McGhee Notes on the use of these slides These slides were created to accompany a presentation. They do not include full documentation of sources, data samples, methods, and interpretations. To avoid misinterpretations, please contact: Eric McGhee (mcghee@ppic.org; 415-291-4439) Thank you for your interest in this work. 44" } ["___content":protected]=> string(191) "

Assessing California's Redistricting Commission - Briefing Slides

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