Cite as: 608 U. S. ____ (2026)
21
Opinion of the Court
this comparator group, we may think of a randomly selected
member of the electorate who has particular voting preferences, or we may think of a randomly selected group of voters who share certain voting preferences. These voting
preferences may be based on a candidate’s party affiliation,
ideology, stance on a particular policy issue, personal charisma, or some other characteristic or set of characteristics.
But whatever they are, the situation of these randomly selected voters must be compared with that of minority voters
alleged to have suffered vote dilution.
This brings us to the final term: “to elect.” As used in
§2(b), this term must refer to the achievement of electoral
victory by casting a ballot.
Putting all these terms together, the baseline is the
chance enjoyed by nonminority voters to secure the election
of their preferred candidates. What, then, is the chance
that any given nonminority voter or group of nonminority
voters has to secure the election of a preferred candidate?
The answer to this question depends on the voting preferences of other voters in the district. For example, in a district where most voters prefer Democratic candidates, a Republican voter in that district will have a low chance of
securing the election of his or her preferred candidate. But
that chance would be substantially higher if the district
were instead filled with voters who prefer Republican candidates. The roster of voters who end up in a given district
depends, in turn, on the districting criteria used by the
State in drawing a legislative map.
If a districting map is produced by computer, as is generally the case today, we may think of all the parameters in
the algorithm that the mapmaker uses. One necessary parameter would be the number of districts required by law,
and another would have to be a range of inter-district population variations that is small enough to comply with the
one-person, one-vote requirement. The algorithm might
then go on to lay out and assign priorities to whatever