This paper provides the first causal evaluation of the political impact of asylum seekers in the UK. Although dispersed across areas on a no-choice basis, political bargaining between central and local governments introduces potential endogeneity in their allocation. We address this with a novel IV strategy exploiting predetermined public-housing characteristics. For 2004–2019, we estimate a sizeable increase in the Conservative–Labour vote-share gap in local elections: a one within-area standard-deviation increase in dispersed asylum seekers widens the gap by 3.1 percentage points in favour of the Conservatives. We find similar rightward shifts in national elections, survey data on voting intentions, and the Brexit Leave vote. UKIP also gains, though less robustly. No effect appears for non-dispersed asylum seekers, who forgo subsidised housing and choose residences independently. Turning to mechanisms, voters move rightward without becoming more hostile towards foreigners. Using the universe of MPs’ speeches, we show that Conservative representatives from more exposed areas emphasise asylum and migration more, with no systematic change in tone or content. Heightened issue salience appears to drive voters’ choices.