What is the reaction of the host society to immigrants’ political integration? We argue that when they win political office, immigrants pose a threat to natives’ dominant position, triggering hostility from a violent-prone fringe, the mass public and the elites. We test these dynamics across UK general elections, using hate crime police records, public opinion data, and text data from over 500,000 newspaper articles. We identify the public’s reactions with a regression discontinuity design of close elections between minority-immigrant and dominant group candidates. Our findings suggest a public backlash against ethnic minority immigrants’ integration into majority settings.