One small point of response to Richard Katz '

We could easily have a repeat of the 2010 UH election in which, at least in the PR segment, both the DPJ and LDP lose votes to anti-tax (and anti-nuclear?) parties.

ESK: it is very dangerous to make any equivalence between the HOC and HOR elections because their electoral systems are so different. Not only is the HOC's local tier SNTV vs. the HOR's SSD , but the HOC has an Open List PR system vs the HOR's Closed List PR.
Thus the personal vote in the Hoc's PR tier counts for more than in the HOR's where it's the party vote that counts most.

Best regards,
Ellis
Ellis S. Krauss
Professor,
Graduate School of International Relations and Pacific Studies University of California, San Diego La Jolla