No one was able to predict Koizumi's win
The result of the election is:
LDP(led by Koizumi) won (from 212 to 296) .
Democratic (led by Okada) lost (from 177 to 113).
Okada, the leader of Democratic party, annouced to resign his position for losing in the election 9/11. One month ago, when Koizumi disolved the parliament and prepared for the election, Okada happily predict the defeat of Koizumi, "I'll resign if I don't get the regime."
He totally misread Japanese domestic public opinion. Not only him, but most of massmedia took the same mistake, criticizing Koizumi's "reckless dissolution".
One of the big mistakes Okada did is that he was just a naysayer. I say again, Democratic party is "not liberal". It is a party supported the biggest labor union and public officials. Never can it be a liberal party. I'd call it the most conservative.
Koizumi's logistic was very simple. He focused only on the privitization of postal service as the first milestone of Japanese reformation, saying "No privitazation of postal service, no econmical growth."
The unbelievable thing is that he knew he would win in spite of the loss of 34 seats which would happen if he persists. The resisting 34 people in his party have threaten him not to dissolve the parliament. No prime ministers ever couldn't do that. Some of them were puppets of "power brokers". Koizumi is going to be the first one who can proceed along his own design.
Just think about the number of seats under Koizumi's influence several years ago. It used to be just 60 (only a small group inside LDP). There are a lot of rivals in the same party who never obey Koizumi's order. In other words, he was not the decision maker even though he was Prime minister. Now he can manipulate almost all the groups in LDP, which means obtaining around 280 seats. He is the "real prime minister" now.