The LDP victory was really overwhelming. With 296 LDP seats combined with coalition partner Komeito’s 31, Prime Minister Koizumi has a two-thirds majority. Under Japan’s constitution, this means even if the upper house (the House of Councillors) again defeated the postal privatization bill, it would not matter, because a 2/3 majority of the lower house can overturn an upper-house veto of a bill.
The result also demonstrates the extent to which the Japanese electoral system is fundamentally majoritarian in spite of containing a mix of single-seat districts and proportional repersentation (with the voter having separate votes in each type of race) that is superficially similar to the “mixed-member proportional” systems of New Zealand and Germany (who also have elections this month).
In fact, as much as this is being spun as a “mandate” for Koizumi and the postal privatization that was almost all he talked about in the campaign, his party obtained only thirty eight percent of the party preference vote. Komeito’s 13.3% brings the coalition up to a bare majority of the votes. This is a net gain of only 1.8 percentage points over the 2003 election for the two parties.
Details of the LDP’s advantage from the single-seat districts in Japan’s system in the Mainichi Daily News today: The LDP won 219 of the 300 single-seat races with 47.8% of the votes cast in these races. (I do no thave the Komeito total in these races, but it would be only a little more, as the two parties do not put candidates up against each other in single-seat districts.)
Also, the postal-privatization rebels (the LDP’s ‘traitors’) held on to only thirteen of the thirty seats they held before the election, losing the rest to Koizumi’s ‘assassins.’
UPDATE: In the comments, RAC provides a more accurate count of the traitors vs. assassins.