Immigrants constitute a potentially disruptive force in democratic political systems in general and that of the United States in particular; that is the conventional wisdom the present chapter will challenge. The contention will be that immigrants tend to be supportive and quiescent citizens notwithstanding the influence of assimilation. This is true for solid and predictable reasons. It is precisely their status as guests that makes immigrants relatively undemanding politically, while their desire to prove themselves worthy members of the American republic tends to make them patriotic These characteristics help to explain what, from the viewpoint of most political theory, is a paradox: despite the cultural heterogeneity of its citizenry, America is a democratic but stable nation with a high level of political integration. It is not territorial amalgamation but immigration that has produced most of the heterogeneity in America, and the difference is crucial. The former process creates resentment; the latter, loyal citizens.