The method of Proportional Representation by Single Transferable Vote (STV) is very elegant from a mathematical standpoint. In fact, it was a mathematics grad student who recently led the campaign to implement STV and IRV (Instant Runoff Voting) at University of California, Davis for its student body elections. He was successful. George Hallett, a co-author of the 1926 book "Proportional Representation" and author of the 1937 book "Proportional Representation: The Key To Democracy", had a doctorate in mathematics.
Political science professor Douglas Amy has researched the use of STV for city councils in America and concluded that the reason that it was repealed everywhere but Cambridge, Massachusetts is that essentially it "worked too well" (see Amy's paper here). In other words, it frightened the existing populace because it gave women and minorities their proportionate share of seats. People in the 1940s and 50s weren't ready to handle that. But in the past 60 years our culture has made a complete 180-degree turn, and not only is diversity in our legislatures accepted, it is encouraged, with special programs designed to "get out the vote" among women and minorities, and the election of women and minorities in our culture is now celebrated.
The time is finally ripe for STV to make a comeback and to make our legislatures and city councils truly representative.