How does having a loved one threatened by detention and deportation impact political participation? Drawing on extant research demonstrating the mobilizing power of a threatening immigration environment, we develop a dynamic theory of what scholars elsewhere refer to as proximal contact. We argue that individuals with proximal connections to punitive immigration policy may be politically mobilized by the belief that immigration enforcement is unfairly targeted at Latinos, but a threatening environment also structures this participation. Individuals are incentivized to withdraw from public institutions, in particular voting, even as they are incentivized to participate in other arenas. We draw on two cross-sectional surveys, one collected in 2015 with a robust oversample of noncitizens and another collected in 2018 of Latinos who are registered voters. We find evidence to support our theory, and in both datasets proximal contact is unrelated to voting, even as it is positively associated with other types of activities like protesting.