WASHINGTON — A closely divided U.S. Supreme Court on Tuesday struggled to decide "what kind of democracy people want," as Justice Stephen G. Breyer put it during an argument over the meaning of the constitutional principle of "one person one vote."
The basic question in the case, Evenwel vs. Abbott, is who must be counted in drawing voting districts: all residents or just eligible voters?
The difference matters, because people who are not eligible to vote — children, immigrants here legally who are not citizens, unauthorized immigrants, people disenfranchised for committing felonies, and prisoners — are not spread evenly across the country. With the exception of prisoners, they tend to be concentrated in urban areas.
Their presence amplifies the voting power of people eligible to vote in urban areas, usually helping Democrats. Rural areas that lean Republican, by contrast, usually have higher percentages of residents eligible to vote.
The court's decision in the case, expected by June, has the potential to shift political power from urban areas to rural ones, a move that would provide a big boost to Republican voters in many parts of the nation.
Chief Justice John G. Roberts Jr. seemed attracted to counting only voters. "It is called 'one person one vote,' " he said. "That does seem designed to protect voters."
But Justice Sonia Sotomayor said there were other interests at stake. "There's a voting interest," she said, "but there is also a representational interest."
Justice Anthony M. Kennedy seemed to be looking for a middle ground. "You should at least give some consideration to the disparity you have among voters" in different voting districts, he said.
The "one person one vote" principle, rooted in cases from the 1960s that revolutionized democratic representation in the United States, applies to the entire U.S. political system aside from the Senate, where voters from states with small populations have vastly more voting power than those with large ones. Everywhere else, voting districts must have very close to the same populations.
But the Supreme Court has never definitively ruled on who must be counted.
Tuesday's case, a challenge to voting districts for the Texas Senate, was brought by Sue Evenwel and Edward Pfenninger. They are represented by the Project on Fair Representation, a small conservative advocacy group that has been active in cases concerning race and voting.
The group was on the winning side in 2013 in Shelby County vs. Holder, which effectively struck down the heart of the Voting Rights Act, freeing nine states, mostly in the South, to change their election laws without advance federal approval. The group is also behind a challenge to affirmative action in admissions at the University of Texas at Austin to be argued today.
In court papers, Evenwel and Pfenninger said that they live in "districts among the most overpopulated with eligible voters" and that "there are voters or potential voters in Texas whose Senate votes are worth approximately 1½ times that of appellants."
Last year, a three-judge panel of the U.S. District Court in Austin dismissed the case, saying that "the Supreme Court has generally used total population as the metric of comparison." At the same time, the panel said, the Supreme Court has never required any particular standard. The choice, the panel said, belongs to the states.
Almost all states and localities count everyone, and the Constitution requires "counting the whole number of persons in each state" for apportioning seats in the House of Representatives among the states. There are practical problems, many political scientists say, in finding reliable data to count only eligible voters.
Federal appeals courts have uniformly ruled that counting everyone is permissible, and one court has indicated that it is required.
In the process, though, several judges have acknowledged that the Supreme Court's decisions provide support for both approaches. The federal appeals court in New Orleans said the issue "presents a close question," partly because the Supreme Court had been "somewhat evasive in regard to which population must be equalized."
In 1990, Judge Alex Kozinski, in a partial dissent from a decision of the federal appeals court in San Francisco, said there were respectable arguments on both sides.
Counting everyone, he said, ensures "representational equality," with elected officials tending to the interests of the same number of people, whether they are voters or not. Counting only eligible voters, on the other hand, he said, vindicates the principle that voters "hold the ultimate political power in our democracy."
In 2001, the Supreme Court turned down an opportunity to decide the question in another case from Texas.