This paper, based on the 2010 Kaohsiung mayoral election, explores candidate ambiguity during the campaign and the corresponding voting behavior under a veil of uncertainty. Current research limits the ambiguity to the candidate’s unclear policy standpoints and disregards the notion that the ambiguity may simply reside in the voters’ own uncertainty. To relieve these constraints, several statistical examinations, including estimating the Condorcet winner, the IIA test under Multinomial Logit, and the Distinguishability test under Stereotype Logit, are proposed to observe how voters directly respond to ambiguity. Among those, Stereotype Logit is especially emphasized and is anticipated to be the most fitting choice model to estimate voting behavior under uncertainty. 
According to the estimation results, there is couple ambiguity observed in this mayoral election: First, despite the outcome of Chen Chu as the Condorcet winner, there is no defined Condorcet loser in this campaign. It indicates that voters’ preferences are not completely organized and transitive. Second, candidates in this election are not mutually independent from the voter’s perspective. People are likely to respond differently if one of the candidates stops the campaign based on the test results. Third, it is especially difficult for voters to distinguish between Yang Chiu-hsing and Huang Chaoshun. Chen Chu, on the other hand, has no ambiguity concern with the other candidates. This paper substantiates that Yang Chiu-hsing, defected from the DPP, mainly to attract pan KMT ballots.