Based on my participant observation of the border militia group known as the Minutemen, this article examines what motivates people to participate in social movements. Building on social movements' scholarship, I argue that participation cannot be reduced to the expression of the beliefs which group members hold. However, while previous scholarship has turned toward organizational dynamics and networks to move beyond the ideological foundations of political behavior, I turn to everyday practices. By focusing on practices, ethnography allows us to expand our understanding of movement participation by showing not just the “before” of a movement (understood as a set of ideas or interests people hold) or the “outcomes” of a movement (understood as securing of material interests) but the “during” of a movement. And, as I show through the Minutemen, the “during” of the movement can sometimes be what inspires and sustains participation, and indeed, be the very crux of what the movement is about.