我國於2024年1月，舉行了第16屆總統、副總統，以及第11屆立法委員的選舉。選舉結果，民進黨提名「賴蕭配」，以相對多數贏得總統，但民進黨在國會以一席之差落居第二大黨，由國民黨取得國會最大黨的地位。這個選舉結果出現了兩個爭議，其一是總統因三強鼎立，再次出現得票未過半的結果；其二是國會出現「矛盾多數」，國民黨無論是區域的黨籍立委或是不分區，得票都是落後給民進黨，卻在轉換為席次之後，成為國會第一大黨。由於總統應選名額只有一個，結果必然是贏者全拿，因此會有相對多數但不及於絕對多數的勝出，可能導致代表性不足的爭議。在立法委員選舉的部分，選制採用並立式兩票制，且小選舉區更佔總席次約2/3，比例代表的部分僅約1/3，因此也可能放大了各黨得票與總席次之間的差異，嚴重者甚至出現選票少但席次高的「矛盾多數」。本文透過既有文獻與制度面的分析指出，只要是贏者全拿的選舉制度，就必然有代表性不足的問題，只是看選制設計而有程度上的差異。另一方面，立法委員的選舉則是受到兩票制席次分配以及選區人口數巨大差異的影響，導致選舉結果不但存在代表性的問題，更可能出現「矛盾多數」的選舉困境。而矛盾多數可藉由制度改革來避免，但贏者全拿的代表性問題，透過制度雖可減緩爭議，但仍可能帶來其他問題。

Taiwan has held the 16th presidential and 11th legislative elections in January 2024. The election result saw Lai Ching-te winning the presidency with a plurality. However, the DPP lost the majority in the Legislative Yuan. This election result sparked two controversies: Firstly, the president was elected without an absolute majority due to the three-party competition; Secondly, the legislature experienced a “contradictory majority” situation, where the KMT, despite trailing behind the DPP in both regional and party list votes, but became the largest party in terms of seats. This article argues that the post-election discussions on whether to adopt a “two-round absolute majority” for the presidency, as well as the contradictory majority in the parliamentary elections,

highlight several controversies in the current presidential and legislative elections. The outcome of presidential election is “winner-takes-all”, which can result in a candidate winning with a relative majority but not an absolute majority. This situation may lead to disputes over insufficient representation. In the case of the Legislative Yuan elections, the electoral system employs a “mixed-member majoritarian system”, with single-member districts accounting for about two-thirds of the total seats, while the proportional representation part makes up only about one-third. This could exacerbate the disparity between the votes received by each party and their total seats, potentially leading to a “contradictory majority”. This article will discuss the issues of electoral systems and proportionality bias, highlighting the reasons for proportionality discrepancies under different systems.