U.S. Supreme Court justices Tuesday weighed a challenge to Arizona’s legislative districts, which claims the maps systematically deprived Republican, non-minority voters of one person, one vote protections guaranteed by the U.S. Constitution. The case, Harris v. Arizona Independent Redistricting Commission, is based on the fact that almost all of Arizona’s Republican-leaning districts are overpopulated, and almost all of the state’s Democratic-leaning districts are underpopulated. A group of 10 Republican voters brought the challenge, claiming these disparities show an intentional attempt to boost Democrats in the state legislature.
In a rare meeting with reporters in early July 1968, Chief Justice Earl Warren answered readily when asked which of the Court’s decisions in his momentous years on the Supreme Court were most important. The series of rulings, he said, that created the constitutional idea of “one person, one vote.” That is a basic theory of democratic representation: no individual’s vote may be weighted more heavily than any other’s. Election districts, for Congress and state legislatures, must be drawn as close to equal in population as can practically be done. The clearest expression of that idea came in the 1964 decision in Reynolds v. Sims. Now, a half-century later, the Court has assigned itself the task of deciding — remarkably, for the first time — how to get to that goal. What, it will answer in one case, population measure should be used: total people in a district, total citizens, total citizens of voting age, total numbers of registered voters? And, in a second case, the Court will answer whether it violates the equality principle if districts are drawn in a way that favors one party’s candidates. Both cases involve cross-currents of political theory, and both have the potential to directly change election outcomes and the election fortunes of the two major political parties. There is considerable complexity here, so let’s try to make this simple.