[J-20-2022] [MO: Baer, C.J.]

IN THE SUPREME COURT OF PENNSYLVANIA

MIDDLE DISTRICT

CAROL ANN CARTER, MONICA 

PARRILLA, REBECCA POYOUROW, 

WILLIAM TUNG, ROSEANNE MILAZZO, 

BURT SIEGEL, SUSAN CASSANELLI, LEE 

CASSANELLI, LYNN WACHMAN, 

MICHAEL GUTTMAN, MAYA FONKEU, 

BRADY HILL, MARY ELLEN BALCHUNIS, 

TOM DEWALL, STEPHANIE MCNULTY 

AND JANET TEMIN,

Petitioners

v.

LEIGH M. CHAPMAN, IN HER OFFICIAL 

CAPACITY AS THE ACTING SECRETARY 

OF THE COMMONWEALTH OF 

PENNSYLVANIA; JESSICA MATHIS, IN 

HER OFFICIAL CAPACITY AS DIRECTOR 

FOR THE PENNSYLVANIA BUREAU OF 

ELECTION SERVICES AND NOTARIES,

Respondents

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PHILIP T. GRESSMAN; RON Y. DONAGI; 

KRISTOPHER R. TAPP; PAMELA GORKIN; 

DAVID P. MARSH; JAMES L. 

ROSENBERGER; AMY MYERS; EUGENE 

BOMAN; GARY GORDON; LIZ MCMAHON; 

TIMOTHY G. FEEMAN; AND GARTH 

ISAAK,

Petitioners

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No. 7 MM 2022

ARGUED: February 18, 2022
[J-20-2022] [MO: Baer, C.J.] - 2

LEIGH M. CHAPMAN, IN HER OFFICIAL 

CAPACITY AS THE ACTING SECRETARY 

OF THE COMMONWEALTH OF 

PENNSYLVANIA; JESSICA MATHIS, IN 

HER OFFICIAL CAPACITY AS DIRECTOR 

FOR THE PENNSYLVANIA BUREAU OF 

ELECTION SERVICES AND NOTARIES,

Respondents

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CONCURRING OPINION

OPINION FILED: March 9, 2022

JUSTICE DONOHUE DECIDED: February 23, 2022

I agree with the selection of the Carter Plan, and I join in the Majority’s analysis, 

including its invocation of partisan fairness as a factor in its selection. Because this case 

requires the Court to select one of thirteen maps, most of which satisfy the four “floor” 

criteria identified in League of Women Voters v. Commonwealth, 178 A.3d 737 (Pa. 2018) 

(“LOWV”), we must use a tiebreaker. In my view, in this circumstance, the logic of LOWV

compels us to consider the degree of partisan fairness among the plans. 

Contrary to Justice Brobson’s suggestion, none of us wish “to serve as the mirror 

on the wall and choose the fairest map of them all.” Dissenting Op. at 8 (Brobson, J.). 

And while Justice Brobson seems to be less opposed to our selection of the Carter Map 

than “the analysis that the majority uses to break a partisan impasse,” the fact remains 

that the political branches have unfortunately thrust the selection of a map on us. Justice 

Brobson fears that we have “invited, not discouraged this Court’s future involvement in 

the congressional redistricting process,” id., but does not set forth an alternative selection 

that would avoid his pessimistic prediction. While which map should be chosen is subject 

to good faith disagreement, we must choose, and “I don’t know” is the one answer we 

cannot give.
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In LOWV, we held that to meet constitutional muster under our Free and Equal 

Election Clause,1 a map must satisfy four neutral “floor” criteria: “compactness, contiguity, 

minimization of the division of political subdivisions, and maintenance of population 

equality among congressional districts.” LOWV, 178 A.3d at 817. The submitted maps 

admirably complied with that dictate.2 The proponents of each map submitted the 

performance metrics corresponding to the neutral criteria.3 Pertinently, virtually all

submissions contained an analysis of how each of their plans performed in terms of 

predicted partisan fairness.

4

 Undoubtedly, this was driven by the following passage from 

LOWV: 

As we have repeatedly emphasized throughout our 

discussion of [Article I, Section 5] the overarching objective of 

this provision of our constitution is to prevent dilution of an 

individual’s vote by mandating that the power of his or her vote 

in the selection of representatives be equalized to the greatest 

degree possible with all other Pennsylvania citizens. We 

recognize, then, that there exists the possibility that advances 

in map drawing technology and analytical software can 

 

1

 “Elections shall be free and equal; and no power, civil or military, shall at any time 

interfere to prevent the free exercise of the right of suffrage.” Pa. Const. art. 1, § 5.

2

I acknowledge that the Carter Plan does not score the best on the floor criteria. See 

Majority Opinion at 27-33. I also agree with the Majority that there are trade-offs involved 

when giving one criterion more importance than others. See id. at 28. Moreover, unlike 

Justices Mundy and Todd, I do not view picking the best plan on these four criteria to be 

an objective exercise. The fact that both Justices wish to pick the plan that best complies 

with the floor criteria but end up favoring different plans illustrates the point. 

Additionally, the parties have largely acknowledged that the 2018 map implemented by 

this Court produced fair outcomes, and, further, that the maps now presented are 

comparable or superior to the 2018 map. Thus, I do not find that the differences on the 

floor criteria are so great that any map can be ruled out on that basis alone. Hence, we 

must turn to a tiebreaker.

3

 See Majority Opinion at 28 n.23 (describing metrics used to evaluate compactness).

4 The Khalif Plan was the only one that did not analyze partisan performance.
[J-20-2022] [MO: Baer, C.J.] - 4

potentially allow mapmakers, in the future, to engineer 

congressional districting maps, which, although minimally 

comporting with these neutral “floor” criteria, 

nevertheless operate to unfairly dilute the power of a 

particular group’s vote for a congressional 

representative. See N.T. Trial, 12/13/17, at 839–42 (Dr. 

Warshaw discussing the concept of an efficiency gap based 

on the number of “wasted” votes for the minority political party 

under a particular redistricting plan). However, as the case at 

bar may be resolved solely on the basis of consideration of 

the degree to which neutral criteria were subordinated to the 

pursuit of partisan political advantage, as discussed below, 

we need not address at this juncture the possibility of such 

future claims.

Id. (emphasis added). 

Although the task of the Court in this matter is distinctly different than the 

constitutional challenge to the enacted redistricting plan at issue in LOWV, the parties in 

this matter obviously recognized that it was not enough to satisfy the neutral factors,

because even though compliant with the drawing requirements, it was important that the 

plan did not “unfairly dilute the power of a particular group’s vote for a congressional 

representative.” Id. 

The purpose of our Free and Equal Election Clause is not to ensure that 

congressional district maps contain clean lines with few divisions and a minimum of 

irregular borders encompassing an equal number of people. It is not a cartography 

lesson. The overreaching objective of this constitutional provision is to prevent dilution of 

a citizen’s vote. Consequently, just as the political branches have an obligation to 

consider partisan fairness when enacting a redistricting plan, so too must this Court when 

put in the position of having to select one from the many that were submitted to us. 

Partisan fairness is not merely a subordinate factor to be considered. When, as here, all 

of the plans are compliant with the floor criteria, consideration of the degree of partisan 
[J-20-2022] [MO: Baer, C.J.] - 5

fairness must, in my view, drive the ultimate selection of a plan in the circumstances in 

which this Court finds itself.5

The degree of partisan fairness is measurable. Measurement is imperfect because 

it cannot account for, among other variables, the quality of candidates. Also, where, as 

here, the submitted plans have no performance record, the partisan fairness metrics are 

predictive, not actual. But the tools are available and widely used. The record in this 

case is replete with expert analyses of the predicted partisan fairness of the plans. 

Admittedly, the data sets used to calculate the metric and, in some cases, the 

methodologies within the designated partisan fairness tests differed among the parties’ 

experts. 

Nevertheless, I do not find that the lack of one perfect test for measuring partisan 

fairness precludes us from considering that factor. It simply means that we should look 

for the most comprehensive review available. Based on the record before us we have 

one comprehensive, comparative analysis of each of the submitted plans’ predicted 

performance on partisan fairness. The Gressman plaintiff’s expert, Dr. Daryl DeFord,

performed an “apples to apples” analysis comparing all plans to each other. In other 

words, he reconciled the data set and methodologies used by the various experts. From 

my perspective, it forms a reliable basis to rank the predicted partisan fairness of the 

submissions. Unlike some other experts, who used limited data sets, Dr. DeFord’s 

 

5

 I do not suggest that any of the plans submitted for consideration reflect a degree of 

partisan unfairness that is disqualifying in a constitutional sense, nor do I suggest the 

level of partisan fairness that a duly enacted congressional district plan must attain. I do, 

however, believe that when this Court is forced to choose among plans, the plans that 

perform the best on partisan fairness metrics must rank above the others. 
[J-20-2022] [MO: Baer, C.J.] - 6

analysis examined “vote totals for [eighteen] statewide general elections[.]” Expert Report

of Dr. DeFord at 5. He elaborated on this point:

For each of my partisan-fairness metrics, I have used election 

results from [eighteen] statewide general elections that took 

place in the Commonwealth between 2012 to 2020. This 

represents the general elections races for U.S. President, 

U.S. Senate, Governor, Attorney General, Auditor General, 

and State Treasurer. This dataset includes examples of 

elections where each of the major political parties’ candidates 

won the overall statewide vote. Many of these races were 

decided by small margins, particularly those in which a 

Republican candidate won the overall election. Thus, I also 

included the 2017 Supreme Court Justice election in my

analysis, as that election had a larger margin of victory for the 

Republican candidate than the other elections had. Looking 

at this breadth of election results helps us better understand 

and model the political geography of a state and related 

realistic vote outcomes.

Id. at 22. 

Dr. DeFord explained that using general elections was useful because “the 

percentages reported reflect the two-party vote share from the two most successful 

candidates, which in these elections were always the Democratic and Republican 

candidates.” Id. at 22-23. Each of the partisan fairness metrics he used “requires one 

first to determine, for each of the [eighteen] general elections, which candidate, the 

Democratic or Republican, carried each of the districts in each redistricting plan at issue.” 

Id. at 23. Then, that information was used “to plot a seats-votes curve, and they also 

become inputs for the partisan-symmetry computations described below.” Id. These 
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results were then used to generate a mean-median score6 and an efficiency gap score.7 

Dr. DeFord then compared all plans to each other on these two metrics, plus four other 

measures generated by the PlanScore.org website. The following table, which is copied

from the Gressman’s Brief in Support of Exceptions at page 59 with slight alterations to 

the headings, reflects the results of that comparison. (In his report, Dr. DeFord indicates 

that a negative score indicates a Republican lean.) 

Partisan Fairness 

Metric

(closer to zero is better)

[Tier one (least bias)] [Tier two] [Tier three (most bias)]

Dr. DeFord’s Average

Mean-Median

(using all 18 elections

from 2012 to 2020)

Sen. Dems 2 (-0.3%) 

Gressman (-0.8%)

House Dems (-0.9%)

Governor (-1.0%)

Draw the Lines (-1.2%)

Carter (-1.6%)

Ali (-1.8%)

Sen. Dems 1 (-1.9%)

Citizen-Voters (-2.0%)

Reschenthaler 2 (-2.6%)

Reschenthaler 1 (-2.7%)

Voters of PA (-2.7%)

HB2146 (-2.9%)

 

6

“The mean-median score is a metric related to partisan symmetry. In simple terms, a 

plan that exhibits partisan symmetry is one that is likely to treat the parties similarly in 

terms of seat outcomes given equal votes received by all candidates statewide. That is, 

if Party A is expected to turn a 55%-to-45% statewide vote advantage into a 10-to-7 seats 

advantage, then a symmetric result would require Party B to turn a similar 55%-to-45% 

statewide vote advantage into a 10-to-7 seats advantage.” Report of Dr. DeFord at 26 

(footnote omitted).

7 We explained the concept in LOWV. 

Dr. Warshaw suggested that the degree of partisan bias in a 

redistricting plan can be measured through the “efficiency 

gap,” which is a formula that measures the number of 

“wasted” votes for one party against the number of “wasted” 

votes for another party. Id. at 840–41. For a losing party, all 

of the party’s votes are deemed wasted votes. For a winning 

party, all votes over the 50% needed to win the election, plus 

one, are deemed wasted votes. The practices of cracking and 

packing can be used to create wasted votes.

LOWV, 178 A.3d at 777. 
[J-20-2022] [MO: Baer, C.J.] - 8

Dr. DeFord’s Average

Efficiency Gap

(using the same 18

elections)

Carter (-0.4%)

Governor (0.6%)

Gressman (0.8%)

Sen. Dems 2 (1.0%)

Draw the Lines (-1.6%)

Sen. Dems 1 (-2.5%)

Citizen-Voters (-2.6%)

Ali (-2.7%)

House Dems (3.3%)

Voters of PA (-4.8%)

HB2146 (-6.3%)

Reschenthaler 1 (-7.8%)

Reschenthaler 2 (-7.8%)

PlanScore Efficiency 

Gap

House Dems (1.2% D) 

Gressman (1.4% R)

Carter (1.8% R)

Governor (1.9% R)

Ali (2.4% R)

Sen. Dems 2 (2.4% R)

Sen. Dems 1 (2.5% R)

Draw the Lines (3.5% R)

Citizen-Voters (4.6% R)

Reschenthaler 2 (6.3% R)

Reschenthaler 1 (6.4% R)

HB2146 (6.6% R)

Voters of PA (6.8% R)

PlanScore Declination Gressman (0.03 R) 

House Dems (0.04 D)

Carter (0.05 R)

Governor (0.05 R)

Ali (0.07 R)

Sen. Dems 1 (0.07 R)

Sen. Dems 2 (0.07 R)

Draw the Lines (0.10 R)

Citizen-Voters (0.13 R)

Reschenthaler 2 (0.18 R)

HB2146 (0.19 R)

Reschenthaler 1 (0.19 R)

Voters of PA (0.20 R)

PlanScore Partisan Bias Gressman (0.9% R) 

Governor (1.1% R)

Carter (1.3% R)

Sen. Dems 2 (1.5% R)

Sen. Dems 1 (1.8% R)

Ali (1.9% R)

House Dems (1.9% D)

Draw the Lines (2.9% R)

Citizen-Voters (4.3% R)

Reschenthaler 2 (5.9% R)

Reschenthaler 1 (6.2% R)

Voters of PA (6.5% R)

HB2146 (6.3% R)

PlanScore Mean-Median

Difference

Gressman (0.4% R) 

Carter (0.4% R)

Governor (0.4% R)

Sen. Dems 2 (0.5% R)

Sen. Dems 1 (0.6% R)

House Dems (0.7% D)

Ali (0.7% R)

Draw the Lines (1.0% R)

Citizen-Voters (1.7% R)

Voters of PA (2.2% R)

HB2146 (2.3% R)

Reschenthaler 1 (2.4% R)

Reschenthaler 2 (2.4% R)

This comparison establishes that four maps submitted for our consideration 

separate them from the field: the Carter Plan, the Gressman Plan, the Governor’s Plan, 

and the second Senate Democratic Caucus plan. The Gressman Plan performs the best, 

with the remaining three all scoring slightly lower. Although the Carter Plan is not the best 

performer, the other plans contain concerning anomalies in their physical configuration. 

Namely, as further explained, those plans make changes that depart radically from the 

historical treatment of certain established communities of interest. Because the Carter 

Plan does not contain these anomalies and its partisan fairness score is nearly identical 

to those other three maps, I agree that it is the best option. 
[J-20-2022] [MO: Baer, C.J.] - 9

The three maps which score better on partisan fairness draw districts that depart 

from historically recognized communities of interest that, in my view, are too drastic for 

this Court to adopt. The most salient of these are: the decisions to split the City of 

Pittsburgh (the Governor and Senate Democratic Caucus) and the decision to place 

Pittsburgh in a district with Washington County along with splitting Bucks County

(Gressman Plan). Communities of interest are in the eyes of the beholder. A 

determination of what qualifies as a community of interest, and what those interests are, 

involves a mixture of local knowledge and political considerations uniquely determinable 

by the political branches within the confines of the floor constitutional criteria. If an 

adopted districting plan resulted in a map that split the City of Pittsburgh and otherwise 

met the LOWV criteria, then the split could be a valid choice. The same could be said for 

the Bucks County split that resulted in a Latino minority opportunity district and the 

combination of the City of Pittsburgh with Washington County based on the rationale that 

they are part of the same standard metropolitan statistical area. From where I sit, I have 

no legitimate way to decide whether the tradeoffs for more substantial compliance with 

the floor criteria involved with these significant changes in the historical treatment of these 

areas are acceptable.

8

 Therefore, I cannot endorse the selection of these maps when 

 

8

 For example, a bipartisan group of current and former Washington County elected 

public officials submitted an amicus brief urging this Court to select any plan but the 

Gressman Plan due to the fact it would create a new congressional district containing all 

of Washington County and the City of Pittsburgh. These individuals argued that 

Washington County and parts of Allegheny County, while “hav[ing] much in common,” 

actually “have little in common[.]” Amicus Brief at 5. Moreover, they predicted that the 

City of Pittsburgh would dominate Washington County. Id. at 6.
[J-20-2022] [MO: Baer, C.J.] - 10

the Carter Map manages not to make those significant changes and still scores very 

highly on partisan fairness. 

Because the outcome achieved in the Carter Plan9 satisfies the LOWV floor criteria 

and is among the best in preventing dilution of an individual’s vote, as demonstrated in 

its partisan fairness metrics, without disrupting long recognized communities of interest, I 

join in its selection as the 2022 Congressional District Plan.

 

9

 As discussed in other opinions, the Carter Plan was designed using the “least change” 

approach. I agree with the Majority that our focus should not be on the method used in 

creating the map – it should be on the outcome. Majority Opinion at 27. 

Regarding whether this Court can apply a clear standard in selecting a map, Justice 

Dougherty favorably cites the “least change” approach used by the Carter Plan 

mapmaker. See Concurring Op. at 3 (Dougherty, J.). Justice Wecht likewise cites that 

approach as a favorable criterion, albeit not as a sole tiebreaker. See Concurring Op. at 

19-20 (Wecht, J.). Justices Mundy and Todd both desire to select the map which best 

follows the neutral floor criteria. See Dissenting Op. at 5 (Todd, J.); Dissenting Op. at 9 

(Mundy, J.). However, this shared belief in the correct standard did not yield the same 

answer. I note that courts in analogous circumstances have asked parties to brief the 

question of whether a clear standard should be adopted. See Johnson v. Wisconsin

Elections Comm’n, 967 N.W.2d 469, 476 (Wi. 2021) (“[W]e ordered the parties to address 

four issues. ... (3) The petitioners ask us to modify existing map using a ‘least change’

approach. Should we do so, and if not, what approach should we use?”). While the 

adoption of a fixed standard is desirable, without the benefit of advocacy I believe this 

Court is ill-equipped to clearly answer that question. For instance, Justice Mundy uses

the “Borda system,” which was not used by any of the parties, and the weights Justice 

Mundy gives to the floor criteria were not subject to examination. In the absence of 

advocacy on the viability of a fixed standard, I believe that it is incumbent upon us to rely 

on the record.