在野黨的選舉策略與優勢政黨的敗選：伊斯蘭黨與2018年馬來西亞國會選舉的實證研究

Opposition Parties' Electoral Strategies and the Defeat of Dominant Parties: An Empirical Study of Parti Islam Se-Malaysia (PAS) and the 2018 Malaysian General Election

馬來西亞自1957年獨立以來，國民陣線（國陣）長期執政，並維持競爭式威權體制逾61年，直到2018年5月才首次政黨輪替。目前探討馬來西亞競爭式威權體制為何垮台的既有文獻指出：馬來西亞都市化的趨勢以及馬哈迪因素是造成執政精英分裂為解釋國陣敗選之兩大可能原因。本文結合政黨政治與族群投票的理論視角，主張伊斯蘭黨的政黨目標改變亦是導致國陣敗選的關鍵因素之一。具體而言，伊斯蘭黨的政黨目標從「追求官職」轉向「追求政策」—為了推動伊斯蘭化政策，伊斯蘭黨退出了過去二十年所加入的在野聯盟，因為民主行動黨時常與其因伊斯蘭議題發生衝突。結果伊斯蘭黨自立門戶之後，反倒成功吸引了那些先前對於伊斯蘭黨與民主行動黨結盟有所疑慮的馬來穆斯林選民。因此，本文假設伊斯蘭黨的參選將會對國陣的選舉表現造成影響。為了驗證這個假設，本文利用馬來西亞半島（西馬）165個國會選區在2018年國會選舉的資料進行量化分析。實證結果顯示，當伊斯蘭黨候選人與國陣候選人在同一國會選區競選時，國陣候選人會獲得較少的選票支持。

Since Malaysia's independence in 1957, the United Malay National Organization (UMNO)-led Barisan Nasional (BN) coalition government governed Malaysia for 61 years, maintaining a competitive authoritarian system. However, Malaysia experienced its first-ever party turnover in May 2018. To understand the reason why Malaysia's competitive authoritarian system collapsed, the existing literature suggests two key explanations for BN's electoral defeat: increasing urbanization, and Mahathir causing a split among the governing elites. Combining the theoretical perspectives of party politics and ethnic voting, this paper argues that Parti Islam Se-Malaysia's (Malaysian Islamic Party, PAS) change of policy objective also was a factor in explaining BN's electoral defeat. Specifically, the PAS changed its goal from “office-seeking” to “policy seeking.” In order to promote Islam, the PAS cut ties with the opposition coalition that it had joined for the past 20 years, because the Democratic Action Party (DAP) conflicted with the PAS with respect to its Islamization policy. The PAS established a new party coalition and focused on promoting Islam, which helped the PAS gain support from the Malay Muslim voters who had not voted for PAS because of its previous alliance with the DAP. Accordingly, this study hypothesizes that the PAS undermined BN's electoral performance. To test this hypothesis, this study conducts a quantitative analysis using data from 165 electoral districts in West Malaysia. The empirical results demonstrate that BN's electoral support was largely undermined in the districts where the PAS contested the election.