摘要： 在如何定义“谁是美国人”，即美国的民族认同这个问题上，美国一直存在两大对立传统，即公民民族主义和传统的族群民族主义。前者以“美国信条”为核心，把美国看作一个价值观的共同体，具有高度的包容性；后者以族群特征为核心，把美国视为一个族群的共同体，具有高度的排他性。从公民民族主义的视角看，美国是一个超越传统民族国家的“例外”国家；而从族群民族主义的视角看，美国只不过是众多民族国家中的一员。在特朗普及其代表的社会力量的推动下，族群民族主义在美国急剧上升。催生这一轮族群民族主义的最重要因素，是文化多元主义以及大量拉丁裔移民导致美国人口结构发生重大变化。从“例外”国家到民族国家的转型势必对美国内政外交产生显著影响，包括移民政策更加缩紧、国内更加分裂、外交更加内向、对国际社会的吸引力更加减弱、对华战略竞争更加尖锐。

关键词: 美国民族认同, 美国信条, 例外论, 公民民族主义, 族群民族主义

Abstract: There are two opposing approaches to America’s national identity: civic nationalism and ethnic nationalism. The American Creed lies at the heart of the former, which makes America an inclusive community of shared political values. Ethnic attributes form the core of the latter, which makes America an exclusive community of selected ethnic groups. The former makes America an exceptional nation, whereas the latter makes it a traditional nation-state. With strong push from Donald Trump and his supporters, ethnic nationalism has witnessed a sharp rise. The major causes of this new wave of ethnic nationalism are multiculturalism, economic plight of the white working class, and the massive influx of Latino immigrants. The Trump administration’s attempts to transform America from an exceptional nation to a traditional nation-state entail significant changes in U.S. domestic and foreign policies, including increasingly restrictionist immigration policy, growing political divide at home, retreat from overseas commitment, decreased attractiveness of America abroad, and intensi?ed strategic competition with China. 

Key words: American national identity, American Creed, exceptionalism, civic nationalism, ethnic nationalism