District Statistics

When you click on “Statistics” in DRA 2020, you see a table of statistics about the districts in your map, side by side for easy comparison.

First Row

The first row in the table is a virtual “district” that contains any precincts that are not yet assigned to districts. The Total column shows the total population for each district, from the Census dataset being used. So, if the value in the Total column in the first row is zero, then all precincts are assigned to districts; if the value is greater than zero, then some precincts are still unassigned.

The first column in the table is, of course, the ID of the district.

The body of the table has four sections.

Population

This section consists of two columns:

• Total — As noted above, this column shows the total population, using the data from the Census dataset being used. You can use this to gauge the degree to which the districts have equal populations.
• +/– —This column shows the population deviation from the target district size, which is the average population of a district (i.e., the total state population divided by the number of districts). Absolute values that are bigger than the generally allowable threshold are highlighted. For congressional districts, this threshold is 0.75%, while for state legislative districts it is 10%.

By default, we use the official 2020 Census data for total population by precinct for maps using 2020 shapes, and the official 2010 Census data for maps using 2010 shapes.

Shapes

This section also has two columns with these icons for headers:

Contiguous/Not Contiguous

Embedded/Not Embedded

• Contiguous/Not Contiguous — The first column indicates whether or not the district is contiguous. A contiguous district is marked with a green check mark, while districts that are not contiguous have a red ‘x’.
• Embedded/Not Embedded — The second column indicates whether or not the district is fully embedded within another district. A “donut hole” district is marked with red ‘x’, while districts that are not fully embedded have green check marks.

Note: Sometimes one or two districts in the official map for a state may show as Not Contiguous, because the shapes in the shapefile aren’t all connected. This can happen when island shapes aren’t connected to mainland shapes (or other islands) or when a municipality consists of two or more areas that are not physically adjacent. We have recently addressed the cases we know about (CA, FL, HI, and RI — 8/1/2020). Let us know if you see examples, so we can address them.

Partisan Lean

Again, this section has two columns:

• Dem — This represents the typical Democratic share (%) of the total (not two-party) vote.
• Rep — This represents the typical Republican share (%) of the total vote.
• Oth — This represents the typical 3rd-party / independent share (%) of the total vote.

These columns combine the results for multiple statewide elections which together better indicate typical statewide voting patterns than an individual election. (See Election Composites for details.) The specific elections used are noted below the ratings diagram in Analytics view. Note: the partisan metrics in Analytics and Advanced views use two-party vote shares, so you want to use an election (or composite) where there the “Other” vote is relatively small.

If the Democratic share is greater than 55%, the cell is highlighted blue to indicate a likely Democratic win. Conversely, if the Republican share is greater than 55%, the cell is highlighted red. The intensity of the color increases as the winning percentage increases.

Demographics

The demographics section of the table starts with:

• Total — Each district’s total voting-age population (VAP) or citizen voting-age population (CVAP), depending on what dataset you have selected.

Note: Using the Data Selector for a map, you can choose to use voting age population (the default) or citizen voting age population (CVAP) demographics for these analytics.

That is followed by seven racial & ethnic demographic breakdowns for each district, shown as percentages of the district’s total VAP or CVAP. To keep things simple, I’ll just use VAP below.

• White — The white only (i.e., non-Hispanic) VAP as a percentage of the district’s VAP.
• Minority — All voting-age minorities as a percentage of the district VAP, where “minority” VAP is the total VAP minus the white-only VAP.
• Hispanic — The Hispanic VAP as a percentage of the district VAP.
• Black — The Black VAP as a percentage of the district VAP.
• Asian — The Asian VAP as a percentage of the district VAP.
• Pacific— The “Native Hawaiian and Other Pacific Islander” VAP as a percentage of the district VAP.
• Native— The “American Indian and Alaska Native” VAP as a percentage of the district VAP.

By default, these columns use the “lone or in part” demographic categories in the 2020 Census Voting-Age Population demographic breakdowns, and the race categories include Hispanics. In other words, these categories may overlap. You can use these six racial & ethnic breakdowns to analyze the opportunity for minority representation.

When a minority percentage reaches 37%, it is highlighted to reflect that it is an “opportunity district” where the minority may have the opportunity to elect a representative. As the percentage of the minority population increases, the intensity of the highlighting also increases.

Last Row

The very last row in the table contains summary values:

• +/– — This value is the overall population deviation percentage. Again, for congressional districts the allowable deviation is typically 0.75%, while for state legislative districts the threshold is typically 10%. Deviations that are greater than the allowable threshold are highlighted.
• Contiguous/Not Contiguous — This indicates whether or not the map is contiguous.
• Embedded/Not Embedded — This indicates whether or not the map contains any districts that are fully embedded within another district.
• Dem and Rep — These values represent the statewide Democratic and Republican shares (%) of the two-party vote.
• White, Minority, Black, Hispanic, Asian, Pacific, and Native— These values represent the statewide proportions of the respective demographic categories.

Notes

After the table, notes can elaborate on important characteristics of the map:

• Unassigned precincts — If any precincts are not assigned to districts, they are noted.
• Empty districts — If any districts don’t have any precincts assigned to them — even if all precincts are assigned to districts — those empty districts are noted.
• Discontiguous districts — If any districts are not contiguous, they are noted.
• Embedded districts — If any districts are fully embedded within another district, they are noted.
• Population deviation — If the population deviation between the districts in the map is not effectively zero, then it is shown along with the the threshold that courts typically allow.
• The Republican/Democratic lean — This note tells you how many seats lean Republican, how many lean Democratic, and how many are in the competitive 45–55% range.
• Majority-minority districts — If the VAP (or CVAP) population for all minorities together is over 50% in any districts, this note reports the number of majority-minority districts.