一般而言對於憲政體制的分類主要是依據總統、行政首長以及國會三者之間的憲政權力、民意基礎以及負責方式等變數,區分為總統制、內閣制以及半總統制三個常見的憲政類型。總統制之下,行政與立法的互動是基於各自的民意基礎與憲政權力,分立政府的出現即建立在兩個不同的民意基礎之上。內閣制之下,行政與立法是來自於同一個民意基礎而建立,當這個民意是少數時即意謂少數政府的建立。半總統制因為同時兼具總統制與內閣制的特質,使得分立政府與少數政府都可能出現。不只如此,由於半總統制將行政權分開為總統與行政首長兩個單位,因此當總統與行政首長分屬不同黨派時,共治更成為半總統制所特有的憲政樣態。以台灣為例,本文認為,憲政制度可以制約行政與立法互動的邏輯,進而影響分立政府、少數政府以及共治等,分別、甚至是一起出現的可能性。
Generally speaking, the most common classification of constitutions is to divide them into three types: Presidentialism, Parliamentarism, and Semi-Presidentialism. In Presidentialism, when the president and the parliament are dominated by different parties, the constitution is operated by a divided government. In Parliamentarism, when the premier and his cabinet are not supported by the majority in the parliament, the constitution is operated by a minority government. Semi-Presidentialism is a mixed type of Presidentialism and Parliamentarism. Therefore, such a mixture may lead to a divided government. At the same time, a minority government also becomes possible. Moreover, the cohabitation will appear when the president and the premier are from different parties. This essay also discusses the possibility that Taiwan's constitution might work concurrently with the divided government, the minority government and the cohabitation.