From the Common Cause plaintiffs’ brief:
The 2016 North Carolina Congressional Plan (“2016 Plan” or “Plan”) is the most overt, and likely the most extreme, partisan gerrymander this Court has ever seen. The official written criteria that governed its creation expressly dictated pursuit of “Partisan Advantage” for the Republican Party and specified a quota of “10 Republican” districts and just “3 Democrat[ic]” ones—despite a near-equal split among the State’s voters….
[T]he First Amendment does not permit the government “to restrict the political participation of some in order to enhance the relative influence of others.” McCutcheon, 572 U.S. at 191. It therefore prohibits State action that distorts “[t]he free functioning of the electoral process” or “tips the electoral process in favor of the incumbent party.” Elrod v. Burns, 427 U.S. 347, 356 (1976)….
The District Court correctly found that [the plan] caused the North Carolina Democratic Party and the voter-plaintiffs to suffer well-recognized First Amendment harms to political expression and association, including “decreased ability to mobilize their party’s base, persuade independent voters to participate, attract volunteers, raise money, and recruit candidates.” … Lastly, the District Court correctly held that this burdening of First Amendment rights was not narrowly tailored to a compelling State interest…
From the LWV plaintiffs’ brief:
As throughout this litigation, the League solely advances a claim of partisan vote dilution under the First and Fourteenth Amendments (while also supporting other plaintiffs’ different claims)….
Republican candidates won ten out of thirteen seats in the 2016 election even though the statewide vote was nearly tied. In 2018—as predicted by Appellees’ expert—Republicans again prevailed in ten districts while Democrats earned a majority of the statewide vote. A Democratic wave thus failed to breach the gerrymander’s defenses. To the contrary, it yielded the single largest Republican advantage in the last half-century of congressional elections….
If given a judicial green light, both parties will exploit their authority to gerrymander even more aggressively, using even more potent techniques, than they have to date. Like North Carolina’s mapmakers, they will ruthlessly crack and pack the opposing party’s voters. They will also program computer algorithms to maximize their partisan advantage and make adjustments throughout the decade to any districts that seem to be slipping from their grasp. Through such machinations, “those who govern,” who “should be the last people to help decide who should govern,” will try to extinguish “the political responsiveness at the heart of the democratic process.” McCutcheon v. FEC, 572 U.S. 185, 192, 227 (2014) (plurality).
Update: Common Cause’s press release and a link to its brief are here.