Do refugees reshape long-term political behavior in receiving areas? I argue that forced migration can foster a strong group identity among refugees, which can mobilize them toward political parties that champion their identity-based grievances. To test this argument, I examine how one of the largest forced migrations in modern history, the expulsion of ethnic Germans from Eastern Europe into Germany after WWII, shaped their electoral behavior over time. Using an original database of district-level data from 32 elections spanning a century, I find that communities which received greater shares of expellees remain more supportive of the expellees’ political champions—the radical right—over time. This relationship is particularly manifested when identity-based grievances are unresolved and politically salient. Mechanism evidence, including novel data on expellee monuments and associations, suggests that a durable expellee identity helps account for these results. My analysis reveals an enduring behavioral legacy resulting from forced migration.