The Supreme Court’s decision today to decide what “one person, one vote” actually means is not all that surprising, at least to many of us. In all the years since the Court recognized that election districts must have equal populations, the Court never squarely resolved what the baseline ought to be for determining “equality” — must districts have equal numbers of residents or equal numbers of eligible voters (which would exclude the young, non-citizens, felons unable to vote)? In 1966, in the earliest days of the reapportionment revolution, the Court did hold that states could choose between equalizing population or eligible voters (Burns v. Richardson, 384 U.S. 73 (1966)). But a lot has happened in the maturation of the law in the ensuing 50 years; in general, the Court has placed greater emphasis on the use of more concrete, precise standards.
Moreover, there is something odd about such a basic constitutional standard under the Equal Protection Clause as the principle of political equality that’s reflected in the “one person, one vote” standard being so ill-defined that states are free to choose whether it’s persons or voters that matter for purposes of equality. Few constitutional standards work that way. In practice, most states have used residents, not voters, for the baseline, but the doctrine leaves open the possibility that states could use other baselines. And as long as the baseline remains constitutionally undefined, states can manipulate the districting system by choosing one baseline over another in order to achieve various partisan or political ends. The difference can be significant, especially in areas of the country — such as Texas, where this case comes from — with large numbers of non-citizen residents.
In addition, since Burns, we have had the emergence of the Voting Rights Act requirements concerning how districts must be designed to avoid diluting the vote of particular minority groups. To ensure political equality in this arena, the baseline for drawing districts has been voters — not residents. Thus, to decide whether a district provides an “equality opportunity to elect” for minority voters, the courts do not look at the total number of minority residents — they look to the total number of voting-age eligible residents. So there is at least some superficial tension between the VRA, where voters are the baseline, and the Equal Protection standard, where most states use population as the baseline. That provides another reason the Court might want to clarify what the right baseline is under the Equal Protection Clause.
Now that the issue is squarely before the Court, my view is that the Court ought to adopt a clear, uniform standard to end uncertainty and potential manipulation regarding what counts as the baseline for the requirement of equality between election districts. Once the Court confronts the arguments on that question, I tend to think the Court will conclude that the best answer is one person, one vote — that it is the requirement of equal numbers of residents (not voters) per district that is critical for constitutional purposes.