Tomorrow the Supreme Court will hear oral arguments in Evenwell v. Abbott, a voting rights case. Evenwell involves the one person, one vote standard the Court developed in the 1960s. In Reynolds v. Sims (1964), the Court held that voting districts that vary widely in population violate the Equal Protection Clause of the Fourteenth Amendment because voters in more populous districts had less voting power than those in less populous districts.

In the Evenwell case, the Court considers the question of how to measure population for purposes of redistricting under the one person, one vote requirement.  Is the proper measure eligible voters or the total number of residents? Currently, total residents is the norm. The challengers in this case argue that when measuring voting district size under the one person, one vote standard, only eligible voters should be counted.  

What to look for in oral arguments in this case? Here are three basic issues that are likely to be on the Justices’ minds.

The Problem of Practicalities. Is it even feasible to move from total population to eligible voter standard? Some argue no: we just don’t have accurate statistics differentiating eligible voters from everyone else. The census measures total population, and this is what most states rely upon now. So even if states wanted to move to an eligible voter standard, they could not do so. The Justices cannot ignore this problem; briefs on both sides engage with the problem. Yet it is important to note that there is something awkward for the Justices about this issue. Constitutional rights are not supposed to turn on the accuracy of demographic metrics. But the Court would surely be hesitant to redefine a right in a way that does not allow for a reliable remedy.

Politics High. Then we have the question of political theory.  What is the basic constitutional value that one person, one vote serves? Is it representational equality, the right to a representative who represents roughly equal numbers of constituents? If so, then total population is the appropriate measure. Or is it electoral equality, the right to have the value of the vote one casts be the same as all other voters? If so, then total eligible voters is the appropriate measure. Each of these theories of democracy has an ample lineage in American history; each also can be supported by a careful reading of the seminal Warren Court voting rights cases. Yet it is hard to say that one or the other is necessarily mandated by the Constitution. Discussions of these issues of political theory are sure to occupy the Justices and attorneys at the oral argument tomorrow.

Politics Low. And finally, we have the elephant in the room, the issue that will be on everyone’s mind but the Justices are not going to want to talk about, at least not directly—the partisan implications of the case. If the challengers get what they are asking for, and the Court issues a decision states to use eligible voters as the measure for inter-district equality, then in many states there will be a shift of power away from urban areas, which generally have a larger percentage of non-eligible voter, and toward rural areas. By most all assessments, this will advantage Republicans. Partisan advantage was a central factor in getting this legal challenge mobilized in the first place, and it has undoubtedly raised the stakes for all sides in this case. If and how this issue arises in oral arguments will be something to watch for.