But what about the many jurisdictions that remain stuck with gerrymandering? Aren’t their voters’ constitutional rights being violated? So the four dissenting justices in Rucho argue. Gerrymandering is “anti-democratic in the most profound sense,” writes Justice Elena Kagan in her fierce dissent.

Not so fast. The Court’s majority has the better of this argument. The Constitution confers voting rights and representational rights on individuals—not on political parties. The whole design of our system is premised on making citizens, not parties, the fundamental locus of political decision making. Political scientists can and do debate whether we might get better results with a parliamentary system, in which voters choose parties rather than candidates. But that’s not the system we have.

What reformers were asking the Court to do, in effect, is give formal, constitutional sanction to parties, by requiring that districts be drawn with an eye not just to representing every vote fairly (that’s one person, one vote), but to representing every party fairly, too, according to its share of the total votes. One can argue for or against that change, but it is much more than a technical or mechanical reform. It is a big step toward parliamentary government—a change in the constitutional order, and one whose results are, again, entirely unforeseeable.