I think this comment by Scott on Michael Turton's blog is a great insight:
Most KMT party members and supporters seem not to believe that China actually means any harm to Taiwan-- and especially not now that there will be a unified KMT government. They believe that the anger of China and the rest of the world is directed solely at Chen Shui-bian and the DPP. They think that if Taiwan's government can just behave, quietly cooperate with Beijing and give up the quest for de jure independence, that China will reciprocate by allowing Taiwan to indefinitely maintain the "status quo" of de facto independence. People voted for Ma because they mistakenly believe he is capable of indefinitely prolonging the so-called "status quo" --which in reality has never been static.
The majority of voters are apparently naive enough to believe that they can keep all of their freedoms and civil rights, while simultaneously acceeding to a gradual accomodation of the PRC's one-China ideology.