這一現象主要源於民主進步黨與台灣民眾黨在黨紀制度與政治運作邏輯上的根本差異，也反映出兩黨對「清廉標準」與「領袖角色」的不同定位。

在制度面上，民進黨長期以來建立了一套被外界稱為「廉政天條」的嚴格規範。根據其《公職候選人提名條例》，凡涉及貪汙、洗錢或毒品等重大犯罪，只要在一審被判有罪，即喪失未來參與公職選舉的提名資格。這種標準甚至高於一般法律上的「無罪推定」精神，目的在於透過高度自律，強化政黨的清廉形象。也因此，像鄭文燦這類具指標性的政治人物，一旦捲入司法案件並進入審理程序，往往迅速被黨內機制邊緣化，甚至在尚未定讞前就退出政治舞台。

相較之下，台灣民眾黨的制度設計則保留了更大的彈性與裁量空間。其《廉政準則》雖然同樣對涉及貪汙等罪行訂有處分條款，但多採取「得予處分」的表述，而非強制性規範，實際是否處分，往往取決於黨中央或中評會的政治判斷。這樣的制度，使得黨在面對重大個案時，可以根據情勢調整立場，但也容易被質疑標準不一。

這種差異在柯文哲的案件中表現得尤為明顯。即使他在 2026 年 3 月一審被判處重刑，由於案件尚未三審定讞，加上本人堅持上訴，民眾黨內部普遍將案件定調為「政治迫害」，並未啟動開除或嚴格處分的程序。更關鍵的是，柯文哲本身不只是黨主席，同時也是民眾黨最核心的政治資產與象徵性人物，一旦依照更嚴格的標準處理，勢必對整個政黨的存續與權力結構造成重大衝擊。

因此，在政治現實考量下，民眾黨目前採取的是一種「保留空間」的策略，一方面維持法律程序尚未終結的正當性論述，另一方面也避免在支持者之間引發劇烈反彈。特別是對所謂「小草」支持族群而言，對柯文哲的信任與情感連結，已經超越單純的法律判決，使得黨內更難在此時進行切割。

整體來看，兩黨的差異不僅是制度條文的不同，更是政黨文化的體現。民進黨傾向以高標準的紀律來維持形象與政治正當性，而民眾黨則更依賴領袖魅力與政治動員，在制度運作上保留彈性空間。這也正是外界批評民眾黨在此案中出現「雙重標準」的根本原因——當過去以高道德標準檢視他人時，如今面對自身核心人物的司法危機，卻選擇採取不同的處理方式。

This situation largely stems from fundamental differences between the Democratic Progressive Party (DPP) and the Taiwan People's Party (TPP) in terms of internal discipline, nomination rules, and political realities. It also reflects how each party balances legal standards, political survival, and leadership dependence.

Within the DPP, there exists a long-standing and highly stringent internal rule often described as a “clean governance red line.” According to its nomination regulations, any party member involved in serious crimes such as corruption, money laundering, or drug offenses becomes ineligible for candidacy once found guilty in a first-instance court ruling. This standard is stricter than the legal principle of “presumption of innocence,” as it prioritizes political accountability and public image over judicial finality. As a result, figures like Cheng Wen-tsan have seen their political careers effectively halted early in the judicial process, even before final verdicts are reached.

In contrast, the TPP maintains more flexible and discretionary internal rules. Its anti-corruption guidelines state that members convicted of serious crimes “may” be subject to disciplinary action, leaving room for interpretation by party leadership bodies. This flexibility allows the party to adapt its response based on political context, but it also opens the door to accusations of inconsistency.

This contrast becomes especially clear in the case of Ko Wen-je. Despite receiving a heavy sentence in a first-instance ruling in March 2026, Ko has not been expelled or strictly disciplined by the party. Since the case is not yet finalized and is under appeal, the TPP has framed the ruling as politically motivated. More importantly, Ko is not only the party chairman but also its central figure and primary source of political support. Enforcing strict disciplinary measures similar to those of the DPP could trigger a leadership vacuum and destabilize the party.

As a result, the TPP has adopted a strategy of maintaining flexibility: emphasizing the ongoing legal process while avoiding decisive internal action. This approach also reflects concern over backlash from Ko’s core supporters, whose loyalty often extends beyond legal judgments.

In essence, the divergence between the two parties is not merely procedural but cultural. The DPP emphasizes institutional discipline and a strict ethical framework to maintain legitimacy, whereas the TPP relies more heavily on charismatic leadership and political pragmatism. This difference explains why critics accuse the TPP of applying a “double standard”—holding others to high ethical expectations while adopting a more lenient stance when its own central figure faces legal challenges.