以前臺灣在政治精英之間才出現的對立，已延伸到一般群眾裡。尤其在總統選舉時，選民之間以情感而非政策立場的對立，已影響臺灣過去五屆總統選舉的結果。本文以「負面黨性」作為觀察臺灣社會「情感極化」的指標，佐以2004至2020年總統選舉，檢證負面黨性對臺灣總統選舉結果的作用。我們發現自2012年開始，對於特定政黨具有負面黨性的選民，百分比呈現大幅上升的趨勢，在2020年總統大選時，已有4成的國民黨和民進黨支持者對敵對政黨有負面黨性，同時給予敵對政黨有史以來最低分。另一方面，即使控制政黨認同及統獨立場，負面黨性對臺灣選民的投票抉擇仍具有顯著的解釋力。也就是說，投票給某一政黨總統候選人的決定，不僅取決於對該政黨的認同，或對其政策的支持，選民對敵對政黨是否具有負面的評價也成為一項關鍵指標。

The bitter rivalries that used to occur only among political elites have now reached the everyday lives of the mass public. In particular, the results of presidential elections have been driven as much by affective conflict between partisans as by policy debates. The present study explores affective polarization in Taiwan through negative partisanship. Data from presidential elections between 2004 and 2020 provide evidence for the effect of negative partisanship on election results. The study found that starting in 2012, there has been a rapid increase in negative views among partisans in both main parties toward the opposing party. In the 2020 presidential election, more than 40% of both Kuomintang (KMT) and Democratic Progressive Party (DPP) supporters showed negative partisanship towards the opposing party. Furthermore, supporters of both parties had the lowest ever favorability scores for the opposing party. Even when traditional party identification and support for independence or reunification are controlled, negative partisanship still has significant explanatory power. The decision to vote for a candidate from a particular party in presidential elections depends not only on one’s long-term identification with that party but also on whether one harbors a strong negative opinion towards the opposing party.