Dallas City Council

How gerrymandered are the Dallas City Council maps?

We report...you decide! See our table below for basic metrics and links to detailed analysis.

PLAN

TITLE

 MM
MM (%ile)
PB
 PB (%ile)
  Favors 2D (#of total)
Ensemble median
   -2.69
 50%
 0
 67.63% N/A N/A
Current map   7.86 99.80% 2 97.83% D 18,722 out of 9,589,284
DCN108910
 Current Districts Corrected Betzen 7.86
 99.8%
 2
 97.83%
 D 18,698 out of 9,589,284
DCN108789
 020322 4.97
 98.05%
 2
 97.83%
 D 113,376 out of 9,589,284
DCN108735
 wip 4.93
 97.99%
 0
 67.63%
 N N/A
DCN108719
 COD-008-Betzen 7.84
 99.79%
 2
 97.83%
 D 19,037 out of 9,589,284
DCN107931
 Betzen Map 31 7.47
 99.72%
 2
 97.83%
 D 25,091 out of 9,589,284
DCN107734
 Betzen Map 30 7.46
 99.72%
 2
 97.83%
 D 25,315 out of 9,589,284
DCN107104
 Betzen Map 25 6.72
 99.48%
 2
 97.83%
 D 41,891 out of 9,589,284
DCN106972
-7.05
 12.73%
 -2
 19.91%
 R 1,201,152 out of 9,589,284
DCN106790
 Betzen Map 20 6.71
 99.48%
 2
 97.83%
 D 42,136 out of 9,589,284
DCN106129
 Betzen Map 17 6.69
 99.47%
 2
 97.83%
 D 42,642 out of 9,589,284
DCN105806
 Betzen Map 15 7.84
 99.79%
 2
 97.83%
 D 19,037 out of 9,589,284
DCN104972
 Attempt to locate 14 population centers -9.82
 2.37%
 -2
 19.91%
 R 227,368 out of 9,589,284
DCN104915
 Betzen Map 11 7.62
 99.75%
 2
 97.83%
 D 22,610 out of 9,589,284
DCN104759
 My PLan2 7.98
 99.82%
 2
 97.83%
 D 16,923 out of 9,589,284
DCN104360
 Lopez 8.76
 99.91%
 2
 97.83%
 D 8,679 out of 9,589,284
DCN103985
 Betzen Map #8 8
 99.82%
 2
 97.83%
 D 16,762 out of 9,589,284
DCN103644
 Betzen Map #6 for submission 8.14
 99.84%
 2
 97.83%
 D 14,887 out of 9,589,284
DCN103506
 Betzen Map #5 for Submission 8.14
 99.84%
 2
 97.83%
 D 14,887 out of 9,589,284
DCN103209
 Betzen Submission #4 8.1
 99.84%
 2
 97.83%
 D 15,298 out of 9,589,284
DCN103191
 COD-005-Tanner -1.09
 65.52%
 0
 67.63%
 N N/A
DCN103120
 COD-006-Betzen 8.85
 99.92%
 2
 97.83%
 D 7,976 out of 9,589,284
DCN102751
 Betzen Final Submission #3 8.85
 99.92%
 2
 97.83%
 D 7,976 out of 9,589,284
DCN102692
 Betzen Submission #3 9.25
 99.94%
 4
 100%
 D 0 out of 9,589,284
DCN102298
 TACW 101464 -1.05
 65.91%
 0
 67.63%
 N N/A
DCN101652
5.78
 98.92%
 2
 97.83%
 D 73,832 out of 9,589,284
DCN101606
 TACW 101464 -0.95
 66.8%
 0
 67.63%
 N N/A
DCN101516
 Betzen Submission #3 5.75
 98.9%
 2
 97.83%
 D 74,989 out of 9,589,284
DCN100997
 Betzen Submission #2 4.8
 97.8%
 2
 97.83%
 D 123,163 out of 9,589,284
DCN100532
 Betzen Submission #1 -3.39
 43.1%
 -2
 19.91%
 R 3,215,999 out of 9,589,284
DCN100113
2.16
 89.83%
 2
 97.83%
 D 312,798 out of 9,589,284
DCN99549
 Betzen 14 Population Center Map Draft 5 -9.82
 2.37%
 -2
 19.91%
 R 227,368 out of 9,589,284
DCN95766
-4
 37.24%
 0
 67.63%
 N N/A
DCN93173
 Betzen Draft 1 -4
 37.24%
 0
 67.63%
 N N/A
DCN92048
 Southern Neighborhoods Fair II -3.31
 43.88%
 0
 67.63%
 N N/A
DCN90091
-1.88
 58.01%
 0
 67.63%
 N N/A
DCN83605
1.06
 83.35%
 0
 67.63%
 N N/A
DCN80589
 Omar's Vision 0.57
 79.8%
 0
 67.63%
 N N/A
DCN80227
 FairMapTX -3.01
 46.82%
 0
 67.63%
 N N/A
DCN79897
 Omar'sVision 1.11
 83.71%
 0
 67.63%
 N N/A
DCN79417
 AGW Plan -5.92
 20.4%
 -4
 0.12%
 R 4,118 out of 9,589,284
DCN79199
 The Cherry Plan 3 -4
 37.24%
 0
 67.63%
 N N/A
DCN78813
 The Cherry Plan 2 -3.73
 39.85%
 0
 67.63%
 N N/A
DCN78748
 Cut with Surgical precision 8.38
 99.87%
 2
 97.83%
 D 12,031 out of 9,589,284
DCN78508
 Hispanic Amplified 0.12
 76.23%
 0
 67.63%
 N N/A
DCN78214
 The Gerrymander Plan 2.89
 93.02%
 0
 67.63%
 N N/A
DCN78158
 The Cherry Plan -3.64
 40.73%
 0
 67.63%
 N N/A
DCN77980
 Perfectly balanced as all things should be -9.08
 4%
 -2
 19.91%
 R 383,259 out of 9,589,284
DCN77653
 Pedrol -5.03
 27.74%
 -2
 19.91%
 R 2,386,799 out of 9,589,284
DCN77510
 Luther Harris Submission -2.77
 49.19%
 -2
 19.91%
 R 3,438,847 out of 9,589,284
DCN77364
-3.29
 44.1%
 0
 67.63%
 N N/A
DCN77286
 Dallas -8.58
 5.53%
 -2
 19.91%
 R 529,330 out of 9,589,284
DCN77202
 Compact/no deviation #cityofdallas 2.18
 89.97%
 0
 67.63%
 N N/A
DCN77188
 TJWPlan -4.93
 28.58%
 -2
 19.91%
 R 2,441,857 out of 9,589,284
DCN77177
 The Best Plan v1.1 -10.34
 1.6%
 -2
 19.91%
 R 153,353 out of 9,589,284
DCN77003
 Young plan -9.13
 3.87%
 -2
 19.91%
 R 370,786 out of 9,589,284
DCN76786
 Edited CD 7.69
 99.77%
 2
 97.83%
 D 21,373 out of 9,589,284
DCN76310
 The Best Plan -10.3
 1.65%
 -2
 19.91%
 R 157,787 out of 9,589,284
DCN76160
 Compact 3.46
 94.92%
 2
 97.83%
 D 211,143 out of 9,589,284
DCN76112
0.83
 81.71%
 0
 67.63%
 N N/A
DCN75471
 Stephen Tordella's Map 2.47
 91.31%
 0
 67.63%
 N N/A

Metrics

MM = mean-median score (expressed as difference in vote share needed for majority)

MM (%ile) = percentile of MM score in ensemble

PB = partisan bias score (expressed as difference in seats won at 50% vote share)

PB (%ile) = percentile of PB score in ensemble. 

Favors = Does the map favor one party relative to another, compared with the ensemble? Possible values: D/R/N (neutral)/NA (not applicable)

2D (# of total) = number of ensemble plans that score worse on both MM and PB, or are equal on PB and worse on MM. We only assessed plans which favored one party over another on both PB and MM; e.g. in contrast S2100 favors Republicans slightly on MM, but is neutral on PB.

For integer-valued quantities such as partisan bias, the percentile value is sensitive to the exact definition. We used an average between the between the "weak" and "strict" definitions (i.e. "less than or equal to" and "strictly less than"), as implemented in the SciPy stats package (stats.percentileofscore(kind='mean') ).


Methodology

We generated an ensemble of 9,589,284 legal Dallas City Council plans using Markov Chain Monte Carlo algorithms as implemented in GerryChain (MGGG, 2018). Data was compiled from the Census Bureau (population data and geographic units) and the Texas Legislative Council (election returns from the 2020 Presidential and US Congress races).  Proposed plans were obtained from the public gallery at DistrictR. Each plan was assessed on a variety of partisan metrics; the range of observed values in the ensemble is then used to assign a percentile value to each metric as computed for each proposed plan.