This article examines the feedback loop between governmental technologies of enumeration and surveillance and Hindu nationalist common sense that creates and sustains what I call "demographic anxiety" about Bangladeshi immigrants andIndian Muslims in the north Indian city of Jaipur. A series of bombings in 2008, rapidly and erroneously attributed to Bangladeshi infiltrators, brought to light the role of these forms of knowledge in struggles over city space and possible urban futures in Jaipur, as well as an incoherent but widespread construction of the demographically aggressive Muslim. I argue that "Bangladeshi" has thus become a mobile signifier that catches up disparate ways of "knowing" local populations. Drawing on personal and research experiences in Jaipur City and newspaper and other media accounts of the bombings, I track the mobilization of this signifier and its material consequences, particularly as they pertain to the fate of Jaipur's "Bangladeshi Basti," which became the site of intense police scrutiny in the aftermath of the bombings. I pay special attention to the ways in which the limits of governmental practices of legibility, such as identity documentation, produce both the will to statistical knowledge and a widespread reliance on common sense that reinforce one another.