The case, Evenwel v. Abbott, poses a question: whether the Constitution’s long-standing “one person, one vote” principle requires equal numbers of voters per district instead of equal numbers of people, as is current practice. Most commentary on the case has focused on its implications for political parties and racial groups. But focusing on the politics, or even on the merits of the constitutional argument, ultimately distracts from a much bigger problem: The data necessary to draw districts with equal numbers of eligible voters does not exist. We have no national citizen database that tells us how many citizens live in each district around the country.