Getting the Math Right: Why California Has Too Many Seats in the House of Representatives

Over the last 40 years of "one person, one vote" jurisprudence, the Supreme Court has distilled a stable and predictable test for resolving the basic numerical issue in equal representation: how much population difference between districts is permissible? Yet there remains one area of representation into which the Court has refused to venture: apportionment of Congress. In its only opinion on the mechanics of the decennial of apportionment, the Court deferred to Congress. It deferred because, unlike districting, it could not find a single workable measure for apportionment. But the reason it could not find such a measure was that it had made a mathematical error.

This Article corrects that mistake and, in the process, shows that the measure of representation for districting should be applied to apportionment. The result is a unified approach to measuring and evaluating disparities in these two types of representation.