1) Every odd year, an 'election' is held but voters vote for parties 2) based 1), seats are distributed using d'Hondt between the parties
3) Also based on 1), districts are modified so that they are gerrymandered to give each party the correct number of seats 4) The following year, those districts are used for the House elections. The results from 1) will give high accuracy info about the distribution of support for the various parties (to the polling station level). This should allow the districting in 3) to be very effective. Ofc, it depends on Congress not closing the 'loophole' that allows districts to be modified more than once per decade. I would also allow in 1) the voters to designate a backup party. If the least popular remaining party has no seats, it is eliminated and votes transferred to the voter's backup until all remaining parties have seats (like PR-STV, but with no surplus distribution). Also, if a party cannot be gerrymandered any seats, maybe it should be eliminated, to allow its supporters votes to be useful. Another question, would it be illegal to restrict candidates so that they must come from the designated party? This would allow each party to run 2 candidates in their district, thus improving choice. ---- Election-Methods mailing list - see http://electorama.com/em for list info