The 5 Serious Problems with the Republican Maps

In a 357-page ruling on September 3, the NC Courts ordered the GOP-controlled legislature to create remedial legislative maps that correct partisan gerrymandering in 14 county groupings in the NC House and 7 county groupings in the NC Senate. The Court’s ruling clearly described the nature of the gerrymanders in each area and ordered the legislature to draw the remedial maps in full public view based on non-partisan criteria.

It should have been straightforward to create fair maps that remedy the gerrymanders identified by the Court. Instead, the GOP created a bizarre plan for drawing the new maps, deciding to select as a base map one of the 1,000 simulated maps entered as evidence in the case by an expert witness, Dr. Jowei Chen, and then adopt changes from there. Dr. Chen’s maps were produced as a statistical tool for testing partisan bias and were not at all guaranteed to fix the gerrymanders identified by the Court.

So it came as no surprise that, while this procedure produced reasonably fair maps in a number of county groupings, it left extreme partisan gerrymanders in place in others.

Using Dr. Chen’s maps as a starting point, Republican lawmakers then tightly controlled an amendment process ostensibly used to eliminate double bunkings, but, in at least two egregious cases, they used that process to give a Republican incumbent a much greater partisan advantage.

When the process was over, the GOP-controlled legislature had, once again, produced partisan-gerrymandered maps for four county groupings in the NC House and one in the NC Senate. It now falls to the Court and its appointed referee, Nathaniel Persily, to insist that these county groupings be drawn more fairly and that, after a decade of anti-democratic, deceitful, and illegal Republican behavior, we finally get fair legislative maps for North Carolina for 2020.

What Would Fair Maps Look Like in the NC House

To understand how the changing maps affect the competitive political landscape in North Carolina, we first calculate the partisan lean of each district based on the vote margin in each NC House district in 2018. We do this for three scenarios: (i) the current maps, (ii) the remedial maps Republicans just passed, and (iii) fair(er) maps based on our estimate of the most likely scenario if the Court orders an independent re-drawing of the four gerrymandered county groupings identified below. We used the 2018 legislative races as a baseline because the political landscape has been changing rapidly in North Carolina over the past several years following national trends.

In the following figure, we order districts by their partisan lean and show the number of NC House seats that are strongly Democratic, strongly Republican, and competitive for both parties under each of the three scenarios based on adjusted* 2018 NC House performance.

Under the proposed remedial NC House map, Democrats would need about a 4.2-point swing relative to 2018 in the most competitive districts to break the majority. This is only a slight improvement from the current maps, which would require about a 5.5-point swing relative to 2018.

*Estimated partisan lean for current maps reflects 2018 election margin in NC House except in NC-H6, NC-H9, NC-H12, NC-H66, and NC-H103 where we have factored in the margin in the NC Senate because 2018 House performance does not reflect the underlying fundamentals in the district.    **We estimate that fair maps would improve the Democratic lean in NC-H43 and NC-H45 by 5 points over the remedial maps; in NC-74 and NC-75 by 8 points relative to the current maps; in NC-H19 and NC-H20 by 4 points relative to the current maps; and in NC-H46 by 5 points relative to remedial maps (reversing the GOP's deliberate gerrymander there).

*Estimated partisan lean for current maps reflects 2018 election margin in NC House except in NC-H6, NC-H9, NC-H12, NC-H66, and NC-H103 where we have factored in the margin in the NC Senate because 2018 House performance does not reflect the underlying fundamentals in the district.

**We estimate that fair maps would improve the Democratic lean in NC-H43 and NC-H45 by 5 points over the remedial maps; in NC-74 and NC-75 by 8 points relative to the current maps; in NC-H19 and NC-H20 by 4 points relative to the current maps; and in NC-H46 by 5 points relative to remedial maps (reversing the GOP's deliberate gerrymander there).

If the Court orders the four most blatant partisan gerrymanders to be remedied, the number of competitive districts would increase significantly. Under these fair(er) maps, it would take only a 1-point swing relative to 2018, giving Democrats a clear shot at the majority in the NC House in 2020.

Here is a brief overview of the four NC House county groupings in which blatant partisan gerrymanders remain:

NC House - Brunswick-New Hanover County Grouping

Adopted Map for Brunswick-New Hanover

Adopted Map for Brunswick-New Hanover

In the southeastern corner of the state, the Court ruled that the Brunswick-New Hanover county grouping was an extreme partisan gerrymander because too many Democratic voters were packed into NC-H18 in Wilmington. Remarkably, the remedial maps do not address the extreme partisan gerrymander at all: NC-H18 remains nearly as packed with Democratic voters, its partisan lean falling from an estimated D+29 to just D+27. As the Court directed, a fair map requires spreading a significant portion of these voters into NC-H19 (a somewhat competitive Republican-leaning district that becomes very secure for Republicans under the new map) and/or NC-H20.

NC House - Forsyth-Yadkin County Grouping

Much like in Wilmington, the problem with the existing maps in the Forsyth-Yadkin county grouping was that too many Democratic voters were packed into just two districts in central Winston-Salem. The remedial maps completely fail to address this extreme partisan gerrymander, leaving NC-H71 and NC-H72 with partisan leans of D+48 and D+45, respectively.

Base Map for Forsyth-Yadkin v. Adopted Map for Forsyth-Yadkin

Base Map for Forsyth-Yadkin v. Adopted Map for Forsyth-Yadkin

The boundaries of NC-H75 in the final remedial map for Forsyth-Yadkin also looks nothing like the base map that was originally randomly drawn, as Republicans carved out the entire eastern part of the district for incumbent Donny Lambeth, moving the partisan lean of his district from R+6 under the current maps to a remarkable R+20 under the remedial maps.

NC House - Cumberland County

The problems in the Fayetteville area have some of the same flavor as Wilmington and Winston-Salem, with an extra twist. In this case, the Court ruled that, under the current maps, NC-H45 was an extreme partisan gerrymander because it systematically traced the Republican-leaning southern and eastern edges of the county. While the new maps address this issue, they introduce two other types of gerrymandering. Democratic voters are now tightly packed into NC-H42 and NC-H44, with partisan leans of D+46 and D+40 – i.e., the remedial maps remain strong partisan gerrymanders.

Partisan map of current district boundaries in Cumberland County v. Adopted map for Cumberland County

Partisan map of current district boundaries in Cumberland County v. Adopted map for Cumberland County

NC House - Columbus-Pender-Robeson

Republicans gerrymandered the Columbus-Pender-Robeson county grouping in full public view during the redistricting process this past week. Under the unconstitutional maps used for the 2018 election, Republicans won NC-H46 by 27 points because they had tightly packed Democratic voters into NC-H47. The selected base map cut the Republican advantage in NC-H46 down to R+3. Clearly alarmed by this, GOP legislators responded by replacing a cluster of Democratic leaning-precincts around Whiteville with a stretch of Republican-leaning districts along the South Carolina state line, increasing their partisan advantage to R+8 and making NC-H46, once again, much safer for Republicans than it would be under fair maps. 

Base Map for Columbus-Pender-Robeson

Base Map for Columbus-Pender-Robeson

Adopted Map for Columbus-Pender-Robeson

Adopted Map for Columbus-Pender-Robeson

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What Would Fair Maps Look Like in the NC Senate

The remedial maps for the NC Senate increase the likelihood that Democrats will hold the seats they won in 2018 and pick up the two remaining GOP-held seats in Mecklenburg and Wake counties, making it much easier to prevent Republicans from regaining a supermajority. Unfortunately, however, the new maps have little impact on the pivotal districts that Democrats would need to win to break the majority. To do that, Democrats will need to win in a couple of places where Republicans won by 6-8 points in 2018. Democrats can win these races in 2020 and break the majority by recruiting exceptional candidates and investing heavily in these pivotal districts. 

Senate.png

The NC Senate maps were more fairly drawn than the NC House districts, but a clear partisan gerrymander remains in Bumcombe County (Asheville area).

NC Senate – Buncombe-Henderson-Transylvania County Grouping

Adopted map for Buncombe-Henderson-Transylvania

Adopted map for Buncombe-Henderson-Transylvania

While the Senate maps are less problematic than the House maps, they also fail to remedy the extreme partisan gerrymander in the Buncombe-Henderson-Transylvania grouping. In this case, the Court ruled that the current maps are an extreme partisan gerrymander because too many Democratic voters were packed into NC-S49 in central Asheville. Republican lawmakers responded by producing a map that does nothing to fix the gerrymander, leaving as many Democratic voters packed into NC-S49 as the current map; the partisan lean of the district is D+31 under both the current and remedial maps.

Note:

For this post, we show the number of competitive districts under each of three scenarios based on voting outcomes in 2018 NC House and NC Senate races. In a number of counties, early voting data for 2018 has not yet been tracked back to precincts by the NC State Board of Elections (NCSBE). To assign the early votes back to precincts, we first calculate early and Election Day vote totals for each 2018 NC House and NC Senate district as a whole. We then assign the early vote back to precincts assuming the Dem over/under performance in during early voting vs. Election Day was the same in all precincts within the NC House and NC Senate district for the counties in which early voting has not been tracked back. We also ensure that the assigned early vote margins fall within 0-100%.

We used the same procedure to estimate precinct level vote margins in 2017 before the NCSBE had tracked back 2016 early voting to precincts, and then we made (minor) adjustments when the final data set was released. No adjustment was large enough to change our “flippability” ranking of a district. For our redistricting analysis, we expect any error related to early vote assignment to be especially small, because the variance of vote margins across precincts is an order of magnitude greater than the within-precinct variance of the error related to early vote assignment.