WASHINGTON — The American Civil Liberties Union weighed in last month on this term’s big Supreme Court voting rights case, the one that will decide the meaning of “one person, one vote.” It took the position embraced by most liberals: that states should be allowed to count everybody in drawing election districts, including unauthorized immigrants, rather than only people eligible to vote.

But the group seemed to take the opposite position in a pair of recent lawsuits it filed in Rhode Island and Florida, in which it objected to counting prisoners when drawing voting districts. Counting prisoners in one district, the lawsuits said, “dilutes the voting strength and political influence” of eligible voters in other districts.

There may be good reasons for treating prisoners differently from other people who cannot vote. But it is also true that counting prisoners, often housed in rural areas, tends to amplify the power of Republican voters. Counting unauthorized immigrants, who often live in urban areas, generally helps Democrats.

What is certain is that neither side in the voting rights case, Evenwel v. Abbott, No. 14-940, has paid much attention to the more than two million people behind bars in the United States.