在分別回顧了歷年來民進黨總統候選人、不分區立委候選人提名制度的變革，並且進一步觀察2007年民進黨總統候選人，以及不分區立委的提名之後，本文發現過濾式民調（排藍民調）的採用，就制度發展層面觀之，是有意在制度面上防堵可能出現的跨黨投票問題。而公開且競爭激烈的總統候選人初選，是具有重要的示範作用的，使得候選人必須接受檢驗，並且必須清楚提出政策主張、表示政治立場的提名方式，不論是對個別政黨，或者對於民眾而言，都是有利的制度。此外，透過民進黨主要總統候選人各縣市得票情況，與不分區立委各派系在各縣市得票的比較。可以明確的得知，一般媒體所謂特定派系能夠大量操控黨員票的說法，是無法獲得支持的。

In this paper we analyze and observe the evolving process of the DPP’s presidential and non-district legislator candidate selection institution, and observe the DPP’s presidential and non-district legislator’s candidate selection process in 2007. First, we find that the adoption of exclusive survey in DPP’s presidential and non-district legislators’ candidate selection is intended to avoid the non-DPP party members’ influence on the result of the survey. In addition, the primary of DPP’s presidential candidate selection is a well-designed institution, because the candidates have to declare his policy position, and political ideologies. Finally, by comparing the primary voting result of DPP’s presidential and non-district legislator candidate selection, we disagree with the view that DPP’s primary voting result was influenced deeply by the factions.