As discussed in our previous post, county clusters are used in the North Carolina General Assembly districts to reduce splitting counties. With the release of the 2020 census data, we can now establish all possible county clusters.
We report our findings in a document written with Christopher Cooper (Western Carolina University), Blake Esselstyn (FrontWater LLC and Mapfigure Consulting), and Rebecca Tippett (Carolina Demography, UNC at Chapel Hill).
The document is linked HERE.
To summarize, we find that 36 of 50 state Senate districts will reside county clusters that are now completely determined. The remaining districts reside in four regions of the state, each with two possible choices of county clusters. When a county cluster only contains a single district, the district is the cluster. In the Senate, ten of the 50 districts are determined via clustering.
In the state House, 107 of 120 districts will reside in county clusters that are completely determined. The remaining districts reside in three regions of the state, each with two possible choices of county clusters. Eleven of the 120 districts are determined via clustering.
We have also examined incumbency within the new clusters. Unless incumbents change address, we find that 4 Senate districts must contain two incumbents (i.e. 4 districts will “double bunk” incumbents). We also find that 5 House districts must contain two incumbents.
We stress that the county clustering process adds a constraint to the redistricting process. Largely, the county clusters do not determine districts and there is still room for the legislature to draw either fair or gerrymandered maps.
Gregory Herschlag
Jonathan Mattingly
