In 1980, in Mobile v. Bolden, the Supreme Court interpreted Section 2 to provide a remedy for such dilution only when the parties could prove that a legislature intentionally sought to dilute minority votes. That standard was almost impossible to meet, for two reasons. First, legislatures rarely announce their discriminatory intent. Second, states can easily come up with pretextual justifications for drawing almost any district line, because such lines can be based on many vague and largely subjective factors, from whether a district is compact to whether it protects incumbents or serves a “community of interest.” So two years later, after widespread criticism of the Bolden decision, Congress amended the Voting Rights Act to make clear that it forbids any districting practice that “results in” denying minority voters an equal opportunity to elect their favored candidates.
Recognizing that Congress had repudiated its prior interpretation, the Court in Thornburg v. Gingles (1986) acknowledged that the law does not require proof that a legislature intended to discriminate, but only that its map had the effect of doing so. In order to establish a violation, the Court explained, plaintiffs had to prove the existence of three objective “preconditions.” First, they needed to show that a minority group was sufficiently large and compact that the state could create a majority-minority district consistent with traditional districting principles. Second, plaintiffs had to show that members of the minority group tended to vote as a bloc, so that they would be able to elect a candidate of their choice if they comprised the majority in a given district. And finally, the plaintiffs were required to demonstrate that the majority also voted along racial lines, thereby frustrating minority voters’ ability to elect their preferred candidate. Once those preconditions were met, the lower courts were to consider the “totality of circumstances,” including other forms of past and ongoing discrimination in the state, to determine whether minority voters’ influence had been diluted. The overall focus, as Congress had made clear, was results—not intent.
There matters stood for forty years. Indeed, just three years ago, in Allen v. Milligan, the Court ruled that Alabama had violated Section 2 by diluting the state’s black vote. Black Alabamians, the plaintiffs showed, were sufficiently numerous to make up majorities in two districts, and Alabamians voted along racial lines—yet the state voting map had only one majority-black district. In its appeal to the Supreme Court, Alabama tried to reinterpret Section 2 to demand a showing of intentional discrimination. But Chief Justice John Roberts, Justice Brett Kavanaugh, and the three liberal justices rejected the state’s reasoning: as Roberts wrote for the majority, it was “patently clear” that because Section 2 liability “turns on the presence of discriminatory effects, not discriminatory intent,” a plaintiff need not demonstrate a “purpose of racial discrimination.” Justice Alito dissented. The standard for establishing a Section 2 violation, he argued, should be reinterpreted in light of subsequent developments to make plaintiffs’ task substantially more difficult. But only Justice Neil Gorsuch joined him.