Many populist parties promote nationalistic country-first policy platforms. In the United States, the Republican Party has increasingly adopted nationalistic policies such as opposition to immigration and multilateralism, culminating in the election of Donald Trump in 2016. The increasing salience of nationalism in American politics raises three important questions. First, has nationalism increased over time? Second, has the rhetoric of leaders within the Republican Party increased the political relevance of nationalism? Third, are White and Black Americans equally susceptible to the Republican Party’s nationalistic appeals, or is its appeal limited to Whites? We examine the prevalence and political effects of nationalism in the General Social Survey national identity modules (1996, 2004, 2014). Analyses yield several clear findings: (1) nationalism and patriotism are positively correlated in the US, equally prevalent among Blacks and Whites, and have not increased over time; (2) nationalism boosts and pride undermines support for anti-immigrant and protectionist nationalist policies; and (3) the link between nationalism and Republican identification has increased over time among Whites but remains nonexistent among Blacks. In sum, our findings suggest that nationalism is stable, whereas its political relevance has increased over time but only among White Americans.