20 RUCHO v. COMMON CAUSE KAGAN, J., dissenting 276. A second expert obtained essentially the same results with maps conforming to more generic districting criteria (e.g., compactness and contiguity of districts). Over 99% of that expert’s 24,518 simulations would have led to the election of at least one more Democrat, and over 70% would have led to two or three more. See Rucho, 318 F. Supp. 3d, at 893–894. Based on those and other findings, the District Court determined that the North Carolina plan substantially dilutes the plaintiffs’ votes.4 Because the Maryland gerrymander involved just one district, the evidence in that case was far simpler—but no less powerful for that. You’ve heard some of the numbers before. See supra, at 6. The 2010 census required only a minimal change in the Sixth District’s population—the subtraction of about 10,000 residents from more than 700,000. But instead of making a correspondingly minimal adjustment, Democratic officials reconfigured the entire district. They moved 360,000 residents out and another 350,000 in, while splitting some counties for the first time in almost two centuries. The upshot was a district with 66,000 fewer Republican voters and 24,000 more Democratic ones. In the old Sixth, 47% of registered voters were Republicans and only 36% Democrats. But in the new Sixth, 44% of registered voters were Democrats and only 33% Republicans. That reversal of the district’s partisan composition translated into four consecutive Democratic victories, including in a wave election year for —————— 4 The District Court also relied on actual election results (under both the new plan and the similar one preceding it) and on mathematical measurements of the new plan’s “partisan asymmetry.” See Rucho, 318 F. Supp. 3d, at 884–895. Those calculations assess whether supporters of the two parties can translate their votes into representation with equal ease. See Stephanopoulos & McGhee, The Measure of a Metric, 70 Stan. L. Rev. 1503, 1505–1507 (2018). The court found that the new North Carolina plan led to extreme asymmetry, compared both to plans used in the rest of the country and to plans previously used in the State. See Rucho, 318 F. Supp. 3d, at 886–887, 892–893.