半總統制已經是當代最多國家採用的憲政類型,對於半總統制的研究也因此逐漸受到重視。由於半總統制被視為兼具議會制與總統制兩種憲政體制的特徵,因此在運作上也可能出現偏向議會制或偏向總統制的可能。然而,在相關的半總統制研究中,主要的文獻仍然集中在兩大區塊,其一是關於半總統制的定義;其二是單一個案或少量個案在運作上的類型比較。結合這兩類的研究探討半總統制轉型的相關研究顯得較為少見。本文以半總統制下政治權力朝向總統傾斜為研究主題,探討在分權型的雙元行政架構下,哪些因素提供了總統擴張其領導權的有利條件。基於行政與立法相互制衡的原則,所謂的總統化也意味著國會無力制衡,或是制衡的權力僅具表面形式化。因此,本文從黨權、國會凝聚度、以及制度上總統對政府與國會的影響力等,這三個變數來比較總統化的強度。其中,總統握有黨權、國會高度凝聚與總統一致、總統又具有制度上的影響力時,政治權力非常容易偏向總統來發展。相反的,總統不具黨權、國會高度凝聚但與總統不一致、總統又不具有影響政府與國會的制度性權力時,權力最不易朝向總統集中。其他的類型則分別提供總統或是總理相互競爭或合作的換軌可能。
Semi-presidentialism gained a narrow plurality of all world countries. The research on the semi-presidentialism is therefore also more and more important. The semi-presidentialism is a constitutional structure which mixes presidential and parliamentary systems. The constitutional operation might tendency toward the presidential system or toward the parliamentary system. However, most literatures focus on either the definition of semi-presidentialism or the single case studies. The research of constitutional transition is relatively rarer. This paper tries to discuss the ”power presidentialization” of the semi-presidentialism. The presidentialization means that the president is superior in the dual executive system. And the supervise of the legislative is in name only. Three independent variables should be paid close attention to this issue. Firstly, if the president is the de facto leader of the ruling party or not; secondly, if there is a stable parliamentary majority or not; and thirdly, if the president is possessed great constitutional power or not. A semi-presidential system will tendency toward a presidential system if all these three conditions are positive.