民眾對於行政首長的評價，無論是在地方層級或是中央層級，長久以來是美國政治學者關注的焦點之一。部分學者指稱民眾對其日常生活品質的認知對行政首長的支持度有著關鍵性的影響；然而，亦有學者指出族群因素同樣扮演著舉足輕重的角色，特別是在地方行政首長的支持度上。本文以美國南方城市紐奧良為研究對象，並以種族因素以及施政表現兩種模式為理論基礎，探討紐奧良市民對非裔市長Ray Nagin 在2005年卡崔娜颶風前後支持度之變遷。藉由分析紐奧良大學調查研究中心所提供之 2004、2006 以及 2007 年「 生活品質研究」民調資料，本研究發現施政表現固然影響民眾對Nagin 市長支持度，然而，種族變數亦展現出不亞於施政表現之影響力，Nagin 市長的種族支持對象在風災前後的劇烈轉變，顯示種族因素是影響紐奧良居民對其市長支持度的關鍵因素。

U.S. political scientists have long been attracted to the issue of how citizens evaluate their chief executive, both in central and local governments. Some scholars claim that people’s perception of the quality of their life makes a huge impact on their approval of the chief executive while researchers of other schools indicate the racial factor is the one playing the most important role in it. This research compares a racial model to a performance model in explaining the approval of the mayor of New Orleans before and after Hurricane Katrina, analyzing the dynamics of job approval of the black mayor, Ray Nagin. By analyzing the 2004, 2006 and 2007 Quality of Life study survey data offered by the Survey Research Center, University of New Orleans, we concluded the findings suggest that the mayoral approval rating is affected by both the factor of race and governance performance. However, the racial model makes an even greater impact on the case of Mayor Nagin than performance model does. The dramatic change of Mayor Nagin’s racial support base before and after Hurricane Katrina demonstrates that race is a crucial factor in influencing New Orleans residences’ approval of their mayor.