We analyze the enacted North Carolina congressional plan (CST-13), the enacted North Carolina House General Assembly plan (SL 2021-175), and the currently proposed North Carolina Senate General Assembly plan (SST-13).
We compare these three districting plans with the ensembles we generated from non-partisan redistricting policies. See here for the congressional analysis and here for the general assembly analysis; these documents contain information on the non-partisan criteria considered along with the resulting ensemble of maps.
As an example, we look at the number of elected Democrats that would have occurred under a range of historic elections. Under each election, we compare the ensemble of non-partisan maps with the enacted map. The enacted congressional plan elects 4 Democratic representatives under a large range of statewide Democratic vote fractions. This level of non-responsiveness is not seen in the ensemble of plans.
We have performed an analysis of the geopolitical landscape of the North Carolina State using the 2020 Census data. We provide a
summary plot derived from an explicit distribution on redistricting
plans. The distribution favors plans with compact districts which keep counties intact.
As the character of the votes considered swing from more Republican to more Democrat, we see a gradual increase in the number of seats won by the democratic party. This responsiveness to the changing opinion of the electorate is consistent with what has been observed when maps are drawn without partisan considerations; either by sampling or by bipartisan committees.