“One person, one vote” is a deceptively simple promise, but a Texas woman wants to clarify which persons count. On Tuesday the U.S. Supreme Court agreed to hear Evenwel v. Abbott, a suit that challenges exactly who should be counted as a person when states draw their district boundaries in pursuit of proportional representation.The plaintiffs are challenging the usual method (counting total number of people living in a district) and are asking that states use the total number of eligible voters instead. The trouble is, we don’t have robust statistics on the number of eligible voters. If the Supreme Court were to set new standards for districting, we would need to overhaul the nation’s statistics and surveys.
Electoral College votes and congressional district boundaries are determined based on Census figures for population. Those numbers include noncitizens, prisoners, felons, children and other people barred from voting. To get from the Census numbers to an eligible voter estimate, a district-drawer would need to make a lot of slightly suspect adjustments.
From the Census numbers alone, it’s possible to calculate the voting-age population (VAP) as a crude approximation of the total number of eligible voters. VAP is just the Census tally, minus everyone under the age of 18. This adjustment wouldn’t placate the plaintiffs of Evenwel v. Abbott, who are more concerned about noncitizens who, provided they’re of age, would still be included in VAP figures. (Sue Evenwel is the plaintiff, and the case is filed against Texas Gov. Greg Abbott.)
But the Census doesn’t ask respondents about their immigration status. In order to get an accurate count of the population, the Census form has to be short and relatively uncontroversial. This encourages people to fill it out without too much inconvenience or fear of the consequences.