The Supreme Court unanimously rejected a challenge by two Texas voters to the “one person, one vote” principle. The plaintiffs argued that Texas violated the Equal Protection Clause by drawing districts that contained approximately the same total population, but varying amounts of eligible voters. Justice Ginsburg writing for the Court held “based on constitutional history, this court’s decisions and longstanding practice, that a state may draw its legislative districts based on total population.”

Texas’ current redistricting practice is to count total population numbers, not just registered voters. The plaintiffs, Sue Evenwel and Edward Pfenninger, argued that their votes were worth less than those of voters in districts with large populations of people ineligible to vote and asked that only eligible voters be counted when drawing legislative and other electoral districts. Justice Ginsburg responded to the argument by stating that nonvoters have important policy interests such as public education, receiving constituent services, and help navigating bureaucracies. By counting those ineligible to vote, such as children, legal and illegal immigrants, and people who have been convicted of certain criminal offenses, they are given a stake in policy debates. Further Justice Ginsburg said using total population numbers is more efficient.

However, the Court did not mandate that total population numbers be used, only that it is not required that states only use eligible voters when making population based district. All 50 states currently base districts on total population.

Justice Thomas concurring in the judgment, but not the rationale, stated, “The constitution does not prescribe any one basis for apportionment within states.” Furthermore, “[the constitution] leaves states significant leeway in apportioning their own districts.” He concludes by saying there is “no single ‘correct’ method of apportioning state legislatures,” and that “the Constitution did not make this Court a centralized politburo appointed for life to dictate to the provinces the ‘correct’ theories of democratic representation…” Thus he could only concur in the judgment.

Justice Alito, who also concurred in the judgment, said the Court had no business addressing the “very difficult theoretical and empirical questions” concerning popular representation in the case, and that he would have chosen not to do so. He further stated that whether a state can use a method other than total population to create legislative districts is an important question that the Court can consider when it has a case with the proper facts to do so.