Paul Edelman has posted this very interesting draft on SSRN. Here is the abstract:

In Evenwel v Abbott the Supreme Court left open the question of whether states could employ population measures other than total population as a basis for drawing representative districts so as to meet the requirement of “one person- one vote” (OPOV). It was thought that there was little prospect of resolving this question soon as no appropriate instances of such behavior was known. That belief was mistaken. In this note I report on the Town of Groton, Connecticut which uses registered voting data to apportion seats in its Representative Town Meeting, and has done so since its incorporation in 1957. The resulting apportionment arguably meets the requirements of OPOV as applied to registered voting data, but badly fails if total population is employed. Thus, it would make a good test case to resolve some of the open questions in Evenwel.