Requirements for Maps

When you click on the “Analytics” command in DRA 2020, the “Requirements” section shows you whether the map meets four general constraints on valid maps.

You’ll see three parts.

Checks

The first part presents the pass (green check) / fail (red ‘x’) tests shown above. See Contiguity for a deeper dive into the nuances & implications of determining contiguity.

Rating

The second part says in plain English whether the map does or doesn’t meet these basic requirements.

Notes

The notes in the third part expand on the checks and identify additional resources for understanding state-specific redistricting requirements:

• 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.
• State-specific requirements — Finally, this note provides links to the Brennan Center’s summary of the state’s specific redistricting requirements and the Princeton Gerrymandering Project’s state-by-state redistricting reforms.