日本「そのつど支持」と政党政治の変容

日本的策略性投票與政黨政治的變化（Changes in Strategic Voting and Party Politics in Japan）

日本政黨政治脫離五五年體制後，社會結構也有所變化。當日本從中流社會轉變為格差社會後，連帶地日本選民的無黨派層擴大，進一步影響政黨在選舉時的策略。故本文從社會、心理、制度要素，依序分析日本高度經濟成長時期中產階級的重要性、90年代無黨派層擴大的背景，以及因應選制改革導致選民策略性投票行為的出現。研究發現，所謂無黨派者，包含了積極的無黨派者、消極的無黨派者，甚或潛在性無黨派者等各種定義。而造成無黨派層意識的變化，主因有保守對抗改革意識形態的弱化、兩黨政治的發展、日本社會貧富懸殊擴大等。故日本無黨派層的擴大以及選民的策略性投票，深刻影響政黨政治的生態，其中最明顯的就是強調黨主席的領導能力。 As Japanese party politics moved on from the 1955 system, the social structure also changes with the paradigms. In other words, the campaign strategies of Japanese political parties are influenced by the growth of independent voters after Japan shifted from a middle-class society to a polarized society. This article analyzes the social, psychological, and structural elements consecutively: 1). the importance of the middle class during the high-growth period of the Japanese economy, 2). the expansion of non-partisan voters in the 1990s, and 3). the emergence of the behavior of strategic voting in response to the electoral reforms. Studies have found the identification of non-partisan voters includes active and passive independent supporters, as well as potential unaffiliated voters. The main reasons for the changes in unaffiliated Japanese voters include the weakening in the opposition of ideologies between conservatives and reformists, the development of the two-party system, and the aggravation of wealth disparity in Japan. Consequently, the rise in unaffiliated voters and strategic voting have an impact on the environment of the Japanese party politics profoundly; where the leadership of party leaders is evidently emphasized.