The 4 reasons the Pa. Supreme Court picked the winning congressional map

This article is part of a yearlong reporting project focused on redistricting and gerrymandering in Pennsylvania. It is made possible by the support of Spotlight PA members and Votebeat, a project focused on election integrity and voting access.

HARRISBURG — In February, the Pennsylvania Supreme Court announced that it had picked a new congressional map for the state — but didn’t explain why.

Now, all seven of the high court’s justices have released opinions outlining their positions, revealing differing perspectives on the judiciary’s role in redistricting and what exactly makes a fair map.

The Democrat-controlled state Supreme Court took over the process after Gov. Tom Wolf rejected a map sent to him by legislative Republicans. The justices considered more than a dozen maps submitted by Wolf, top lawmakers, good-government groups, and voters.

In a 4-3 decision, the court picked the map put forth by the Carter petitioners, a group of Pennsylvanians who brought one of the original lawsuits asking the judiciary to intervene in the redistricting process.

Their map was drawn by Jonathan Rodden, a political science professor at Stanford University, and closely resembles the current one.

The majority opinion — written by Chief Justice Max Baer, a Democrat — outlined four reasons why the Carter map was chosen.

“There is no perfect plan, nor can there be, as many of the criteria work at cross-purposes to each other and require mapmakers to balance opposing criteria,” Baer wrote. “Our task is to discern which plan, in our view, best abides by the traditional core criteria with attention paid to the subordinate historical considerations and awareness of partisan fairness.”

Here’s a rundown of the justices’ arguments for and against the map:

The Carter map fulfilled traditional core criteria

In a monumental 2018 decision, the state Supreme Court threw out the Republican-drawn map passed in 2011, finding it violated the Pennsylvania Constitution.

In that ruling, the justices outlined four neutral redistricting criteria meant to provide a floor of “protection for an individual against the dilution of his or her vote in the creation of [congressional] districts.”

Those criteria are compactness, contiguity, minimal splits, and equal population. The Carter map fulfilled all of them, but it didn’t score as well on some of these metrics as other maps.

Baer acknowledged that the Carter map “is slightly less compact than some of the other maps,” but he said that was the result of a justified tradeoff to minimize the splits of political subdivisions.

The Carter map considers secondary criteria used in past redistricting cases

Past precedent allows the state Supreme Court to consider other criteria such as incumbency, communities of interest, and preservation of prior districts. However, these criteria are subordinate to the neutral criteria previously outlined.

The Carter map’s approach was to change as little as possible from the 2018 map that the Supreme Court put in place and previously deemed satisfactory. Nearly 87% of the population remained in the same district, despite the state losing one of its 18 congressional seats. The next closest plan kept 82% of the population in the same district.

Baer wrote that the Carter map sufficiently considered communities of interest, citing its decision to keep Pittsburgh whole and to unify Carbon County with the Lehigh Valley area in one district.

The Carter map intentionally considered incumbency in order to avoid “inadvertently double-bunking sitting congressional representatives in the same district,” Jonathan Rodden, the professor who drew the map, wrote in a report to the court. To account for significant population loss in rural areas and growth in the southeast, two incumbents were paired.

The Carter map doesn’t dilute a voter’s power

The Free and Equal Elections Clause of the state constitution, which guarantees that each vote has the same amount of power, was at the heart of the 2018 ruling and again played a significant role in this case.

“For our form of government to operate as intended, each and every Pennsylvania voter must have the same free and equal opportunity to select his or her representatives,” Justice Debra Todd wrote on behalf of the majority at the time.

In the same ruling, Todd wrote, “It is axiomatic that a diluted vote is not an equal vote, as all voters do not have an equal opportunity to translate their votes into representation.”

“Pennsylvania was one of the first that recognized that partisan gerrymandering as a violation of the state constitution,” Michael Li, senior counsel for the nonpartisan Brennan Center’s Democracy Program at New York University, told Spotlight PA.

To gauge if any group’s voting power had been diluted, the court considered a number of fairly new metrics including the efficiency gap, which indicates the number of “wasted votes” in each election or the number of votes that don’t contribute to a candidate’s victory.

The difference in efficiency between the two parties should be as small as possible to represent an unbiased map.

“The Carter Plan had the least biased score (-0.4%) on the average efficiency gap metric,” Baer wrote.

According to Rodden’s analysis, each major party is expected to win eight districts under the Carter map with the one remaining district a toss-up that has a slight Democratic lean.

The Carter Map appears to abide by the Voting Rights Act

The federal Voting Rights Act requires that maps do not dilute voters’ power based on race.

Baer wrote in his opinion that “formal Voting Rights Act assessments were not performed,” but he noted that the Carter map retained two existing majority-minority districts and that the current map has not been challenged for violating the law.

Why some of the justices dissented

Four justices ruled with Baer, while the remaining three dissented for various reasons.

Todd, a Democrat, argued that the Gressman map — drawn by a group of scientists and mathematicians from Pennsylvania universities — best fulfilled the traditional criteria outlined in the 2018 redistricting case. She disagreed with the use of “subordinate historical criteria,” saying there was no need to look beyond the neutral redistricting criteria.

“In my view, assessment of subordinate or secondary considerations such as partisan fairness, or whether a plan represents the least change from a prior congressional districting plan, is necessary only when a court must choose among various plans that are equal with respect to their compliance with the core criteria,” Todd wrote.

Justice Sallie Mundy, a Republican, also dissented, agreeing that the court should only use neutral redistricting criteria previously outlined to select a map in order to remove any perception of political bias.

“In addition to maintaining the appearance of neutrality, it helps avoid any subtle, unconscious influence that political considerations might otherwise bring to bear upon our decision-making,” Mundy wrote.

Justice Kevin Brobson, a Republican, cautioned that the court was overreaching in its selection of a reapportionment planning, advising it to “hew closely to nonpartisan standards or nonpartisan methods, eschewing partisan considerations or partisan approaches.”

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