This article uses the case New York City to examine why certain immigrant groups participated in the 2006 protest wave more than others and why the city mobilized less compared with other major immigrant metropolises. The findings indicate that certain immigrant groups participated more than others because of how the issue of "illegal immigration" was racialized and framed by the media, and because of the disproportionate impact the proposed legislation would have had on them. The data presented illustrate how the city’s heterogeneous population served to diminish its capacity to produce the magnitude of mobilization found in other large immigrant cities.