I cannot argue with Okumura-san's calculations. On the basis of the known numbers, the margin of victory could likely be a lot narrower than many are supposing.
However, I find myself more inclined to agree with the caveat Okumura includes at the end of the post than with his main argument:
Of course the DPJ is currently enjoying much larger advantages in public opinion polls than would accompany the kind of voting patterns that would give the DPJ “only” 77 seats. If it can maintain that kind of lead on 30 August, and given the assist from the rest of the opposition, it's a safe bet that it will win an overall majority on its own.It is not just the gap in the popularity ratings of the DPJ over those of the LDP that indicate a win for the DPJ. What will have a much greater impact will be turnout. This will be true in both the proportional vote in the regional blocs and in the single member districts. Given the long time lag since the last House of Representatives election, the failure of three LDP prime ministerships in the meantime, the global economic crisis, the numerous looming and consistently mishandled demographic crises, the unfortunate timing of election (the day before the start of the new business quarter and the end of school summer vacation) and the pent-up frustration of 50 years of misrule, chances are that voter participation will be way up above the long-term trend line.
In a land of machine politics victory margins are by necessity slim. Budgets are not infinite and every single vote for a machine candidate has had to have been to be paid for in some way. When voter turnout rises, votes start coming in from those in the electorate who have not been bought, meaning those who have a vested interest in toppling the intolerable, clientalist status quo rather than in perpetuating it.
Furthermore, the LDP has lost the aura of leadership. It has been fighting a 30 year rearguard action against the electorate, a war of attrition with the popular will that has saddled the state with debts equivalent to those incurred by countries engaging in actual world wars. Unable to control even its own members, much less events, it is reduced to playing word games and conjuring up insulting stereotypes (Is the electorate really a beautiful woman one is trying to seduce?). The party is engaged in a desperate last minute effort to emphasize its experience, oblivious to the public's full awareness that the experience the party is promoting is on how to a brilliant and hopeful country into the ground.
For all our trappings of civilization, we are apes of the African plains. We can sense when the leader can no longer lead the group, when he defends his shortcomings by gibbering about past glories and his undiminished vitality, despite his years. We sense the unforeseen instant when one has to gravitate to the new leader, no matter how unlikable or untrustworthy he may be...when it becomes clear that he is in the ascendant. It takes a supreme act of self-delusion, a mania, to cling to the past in these instances -- and most of us are savagely sensible.
We are a pitiless lot when our own interests are at stake.
Later - This post has been edited for greater clarity.