Over at GlobalTalk 21, Okumura Jun explores the Sentaku movement in detail.
I would only wish to underline two points touched upon in Okumura-san's impressive review of the goals and attributes of this two-headed (local government and central government) political reform organization.
The first is the existential point: if local government officials and the younger generation of Liberal Democratic Party and Democratic Party of Japan members in the Diet feel it necessary to form an organization that has a goal of pressuring the party leadership to produce meaningful policy manifestos--then local government officials and the younger generation of LDP and DPJ members have no confidence in the standard operating procedures of the parties as regards the production of meaningful manifestos.
Manifestos, yes...meaningful ones, no.
As for what "meaningful" might mean in a concrete sense, it probably means (gosh I hope it does) manifestos that recognize the necessity for tradeoffs and sacrifice--that do not, as the famous joke about the idiot manager's recommendation says, "focus our attention and energy across the board."
The second point is regarding the relative youth of the participants. While the principle of "the lower the number of elections to the Diet, the more untainted the politician" may be a good rule of thumb (depressing as it may be) such a rule may not hold up under scrutiny. Unless the Sentaku membership declares in advance from what pedestal it intends to address the excluded elder statesmen of both the major parties, I do not predict respect from the press.