This paper studies the long-run political consequences of forced displacement when refugees carry distinct political ideas. With the collapse of the Spanish Republic in 1939, 500,000 left-wing leaning refugees fled into France, where logistical constraints quasi-randomly determined refugee camp locations. Exploiting this setting, we identify the causal effect of refugee exposure on political behaviour. Exposed municipalities shift away from Socialist support toward the Communist Party and display greater resistance activity and left-wing associational life, consistent with the diffusion of political ideas. Drawing on new individual-level data, we show that refugees concentrated near camp sites over the long run, providing a demographic channel through which political effects persisted and resurfaced in local political participation patterns decades later.