Thursday, April 21, 2022

Comparing Dallas City Council District Map proposals for winnability

Below is a chart of the Dallas City Council Redistricting maps being studied for selection by the Commission and then to use as a platform for any amendments needed. They are the maps that best achieve the Civil Rights goals of maximizing minority participation in our Dallas City Government. These maps produced the most districts that have the highest potential for selecting a minority candidate. It is clearly shown that 9 winnable minority districts are possible. It also shows that 5 winnable Black Districts are possible but not without destroying the potential for a 4th Hispanic District and a 9th winnable minority opportunity district.

In an attempt to measure winnability three different measurements were used: ppb, pph, and ppw. They tell the strength of a minority group in winning a district by telling you how many percentage points exist between the highest VAP (Voting Age Population) percentage racial/ethnic group in a district and the next highest percentage racial/ethnic group. It then identifies that second-place group as either Black, Hispanic or White-Non-Hispanic. This measurement system is used throughout the chart to achieve some objectivity. Since we know CVAP percentages are generally only about 61% of Hispanic VAP percentages but average over 30% higher than Black and White-non-Hispanic VAP percentages, we can make winnability estimations accordingly.
Obviously, this is only a crude measure, but it lends some level of objectivity to a very human process.
To double-check the calculations I have made in this chart it is recommended you randomly select any number in the chart and check it with the identified map
VAP data for the district you want to check. Please let me know immediately if you find any errors. I hope there are none, but it is very possible as this involved multiple calculations.
The numbers 1, 2, 3 & 4 at the top of the four columns for Black Districts and for Hispanic Districts are simply to identify the columns and not to be confused with district numbers. The goal is 4 winnable districts each plus the Minority Opportunity District in the last column as the ninth winnable district.
I value any questions you may have. The chart is below.