I am not an expert on the subject but I recall talking to people about how it worked in Illinois.  The problem was that the minority party representative in Downstate (non-Chicago Illinois) was often a placeman for party bosses who managed to control the nomination process and then easily win the seat.  This helped increase the power of political machines and party bosses within the state legislature.  People resented the minority party representative because they were not seen as representatives of people in the area.  (Perhaps someone from Illinois knows more?)

This is related to the crucial role of the magnitude of seats in a district under alternative election systems.  Cumulative voting with three seats in a district does provide representation for the minority party in areas where they would otherwise get none.  On the other hand, in a two-party system, it may result in more than two-thirds of the seats being safe for one-party or the other.  Cumulative voting results are somewhat hard to predict for a variety of reasons.  However, assuming that (1) all votes are cast for the two major parties, (2) the minority party all plumps for one candidate, and (3) the majority party maximizes the efficiency of its vote by spreading it perfectly among three candidates, the majority party would have to win greater than 75% of the vote before the minority party would lose its seat.  On the other hand, the smaller party would have to run two candidates (risking its hold on its one seat) and cross the 50% threshold to get another seat.  In seats with a stable majority for one party between 50 and 75%, one can predict the electoral outcome with a fair degree of certainty.

 

In short, cumulative voting may ironically lead to a different form of the "monopoly politics" complaint made by cumulative voting advocates against the first-past-the-post system widely used in the U.S.

 

Of course, the same problem can occur even under proportion systems (like D'Hondt) with magnitudes of only three seats.  One solution is to raise the magnitude of the seats, but this tends to undercut the territorial link to legislators that is so valued under the current system.

 

Regards,

David Lublin

American University