半總統制下總統的黨政運作與執政黨的總統化：蔡英文總統執政時期的研究

The Operation of the President’s Party-Government Relations and the Presidentialization of the Ruling Party under Semi-presidentialism: A Study of Tsai Ing-wen’s Presidency

本文探討臺灣半總統制下有關黨政關係兩個並存而相關的重要現象：總統的黨政運作機制，以及執政黨出現總統化的現象，並以蔡英文總統執政時期為例。本研究指出，同時影響總統黨政運作和政黨總統化的變項，在於總統是否兼任黨主席這項因素。本文並以三個主要指標觀察政黨的總統化：黨主席與總統職位的關係、總統對執政黨所施加的政策影響、總統對執政黨公職候選人提名的影響。研究顯示，蔡英文執政時期多數時候由總統兼任民主進步黨黨主席，黨政運作機制以總統為核心，並形成政黨的總統化現象。然而，無論蔡總統兼黨主席與否，民進黨的總統化現象都存在，但兼任又比未兼任時程度高。本研究並以一個輔助性指標：「政府的黨性」，作為觀察政黨總統化的另一種參照。結果顯示，政黨越從屬於總統，在受到總統影響的內閣組成上，其中無黨籍閣員的比例越高。最後，比較憲政體制因素與基因起源因素對於政黨總統化現象的解釋力，本研究關於民進黨個案經驗的顯示，憲政體制因素則明顯扮演更決定性的作用。

This article explores two coexisting and related important phenomena related to party-government relations under Taiwan's semi-presidential system: the president's party-government operating mechanism, and the phenomenon of presidentialization of the ruling party, taking the period of President Tsai Ing-wen's administration as an example. This study points out that the variable that affects both the president's party-government operations and the presidentialization of the party is whether the president concurrently serves as the party chairman. This article examines the presidentialization of political parties through three main indicators: the relationship between the party chairman and the presidency, the policy influence exerted by the president on the ruling party, and the president's influence on the nomination of candidates for public office by the ruling party. Research shows that most of the time during Tsai Ing-wen's administration, the president concurrently served as chairman of the Democratic Progressive Party. The party and government operating mechanism centered on the president, forming a phenomenon of presidentialization of the party. However, whether President Tsai is also the party chairman or not, the phenomenon of presidentialization of the ruling party still exists, but the degree of presidentialization in the ruling party is higher than when she is not concurrently serving. This study also uses an auxiliary indicator:“partyness of government”as another reference for observing the presidentialization of political parties. The results show that the more subordinate a party is to the president, the higher the proportion of cabinet members without party membership in the composition of the cabinet that is influenced by the president. Finally, by comparing the explanatory power of constitutional institutional factors and genetic origin factors on the phenomenon of presidentialization of political parties, this study’s case experience of the DPP shows that constitutional institutional factors obviously play a more decisive role.