In 2011, with Republicans at the helm, the Wisconsin state legislature melted down the state assembly districts to remake them in its own image. The resultant redistricting plan was so skewed to favor Republicans that, although Democrats captured a majority of the popular vote in the three statehouse elections since the redistricting, Republicans won 60, 63, and 64 of the state's 99 assembly seats. In November of 2016, a panel of three federal judges ruled the map to be an "unconstitutional partisan gerrymander," deeming its dilution of Democratic votes to be unexplained by the state's political geography. The following year, the Supreme Court took up the case, known as Gill v. Whitford. During oral arguments, the justices indicated a shared abstract distaste for partisan gerrymandering, and it appeared the ruling would come down to whether the court had found a quantifiable standard for when to intercede and how to remedy the most egregious cases. One yardstick suggested by the plaintiffs was the "efficiency gap," a tool developed by political scientists that calculates the number of "wasted" votes—in less competitive races, more votes are wasted. Though the liberal justices were quick to point out that the politicians drawing the maps relied heavily on social science data, the more conservative Chief Justice John Roberts expressed discomfort in basing court decisions on what he called "sociological gobbledygook." Neil Gorsuch seemed wary of any standard at all, comparing the redistricting process to the seasoning of a steak: "I like some turmeric, I like a few other little ingredients, but I'm not going to tell you how much of each." The June 2018 opinion ruled that the plaintiffs did not have standing to challenge the statewide map. But instead of dismissing the case, the court made the unusual move of sending it back to a lower court for Wisconsin Democrats to reestablish their standing (likely through challenging voter dilution in individual districts, rather than challenging the entire map).
Maryland's 6th congressional district slinks along the state's northern border, reminiscent of the 19th-century cartoon salamander from which gerrymandering gets its name. A 2011 redistricting process led by Maryland Democrats dramatically altered the shape and political composition of the district. In the first election under the new map, the Democratic candidate won by over 20 percent, unseating a Republican incumbent who had held the seat for two decades. Unlike in Wisconsin, this case (Benisek v. Lamone) is not a challenge to the entire statewide map, but to a single district. Though the full case has not yet been decided by a lower federal court, in March of 2018 the Supreme Court heard oral arguments to determine whether to prevent Maryland from using the current district map until a final decision is made on its constitutionality. It's unambiguous that Maryland Democrats rejiggered the 6th district for political gain: Governor Martin O'Malley admitted as much under oath, and a report by the Baltimore Sun showed that officials made an effort to cloak the self-serving redistricting by exempting the process from Maryland's open-meetings laws. Though the simple measurement of voter dilution proposed by the plaintiffs (that any new map that dilutes a party's strength in a district is unconstitutional) is relatively gobbledygook-free, the case's central question is similar enough to Gill that Justice Stephen Breyer floated the idea of combining the Maryland and Wisconsin cases into a giant partisan-gerrymandering bonanza. Other justices, including Elena Kagan, worried that the proposed standard was so simple that it would prevent any future redistricting whatsoever, even the non-partisan kind. On the same day it kicked the Gill can down the road, the Supreme Court released an unsigned, unanimous opinion sending Benisek back to the lower court, stating that Republicans had waited too long to prevent Maryland's use of the map in the 2018 elections.
Before the narrow rulings in Gill and Benisek, the Supreme Court's last word on partisan gerrymandering was a 2004 decision in Vieth v. Jubelirer not to strike down a Pennsylvania redistricting map. However, the court—and, most significantly, Justice Anthony Kennedy—expressed a willingness to strike down more-extreme examples of partisan gerrymandering in the future, if a clear standard for unacceptable cases could be reached. In February of 2018, Pennsylvania's Supreme Court struck down the state's 2011 congressional map—drawn by Republicans—ruling it to be in violation of the state constitution's clause requiring elections to be "free and equal," and describing one of the districts as "Rorschachian." In addition to a new, court-ordered map for Pennsylvania's 2018 elections, the ruling illustrates a potential road-map for state court challenges to gerrymandering across the nation, as most state constitutions contain similar protections.
In 2016, the Supreme Court struck down North Carolina’s 2011 redistricting map— created by state Republicans with racial data in hand—as a violation of the Voting Rights Act. Ordered to produce a less explicitly racist map, North Carolina Republicans hired a consultant from the Republican National Committee and issued directions to "minimize the number of districts in which Democrats would have an opportunity to elect a Democratic candidate." David Lewis, the state assemblyman tasked with redistricting, was admirably candid: "Electing Republicans is better than electing Democrats," he said. His plan got results: In the 2016 election, state Republicans received 53 percent of the vote but 77 percent of congressional seats. But, in a decision reminiscent of Groundhog Day, a unanimous panel of federal judges in 2018 found the map's favoring of Republicans to be a violation of the Constitution's equal-protection clause. The ruling came only a month before candidates were required to file for the 2018 congressional elections, bringing a week of uncertainty until the Supreme Court told the state not to revise the map before it could rule on the merits of the case itself. However, in June, the Supreme Court declined to hear the North Carolina case on appeal. As with the Wisconsin case, it ordered the federal district court to reconsider the plaintiffs' standing.