This article synthesizes research on political outcomes associated with increasing immigration, with an emphasis on cross-national studies of European countries, where immigration is a relatively newer phenomenon compared to the United States and other traditional immigrant destinations. We begin with explanations of and research on anti-immigrant sentiment, not a political phenomenon in itself but considered an important precursor to other relevant political attitudes. Next, we review scholarship on the relationship between immigration and support for the welfare state, as well as exclusionary attitudes regarding immigrants’ rights to welfare benefits. Then, we review research on immigration and political party preferences, in particular radical right parties, whose platforms often combine anti-immigration and welfare chauvinistic positions. We conclude by discussing how these processes may ultimately shape social policies, which may in turn influence immigration itself.