Why, in the aftermath of 9/11, did a segment of U.S. security experts, political elite, media and other institutions classify not just al-Qaeda but the entire religion of Islam as a security threat, thereby countering the prevailing professional consensus and White House policy that maintained a distinction between terrorism and Islam? Why did this oppositional threat narrative on Islam expand and even degenerate into warning about the “Islamization” of America by its tiny population of Muslim-Americans—a perceived threat sufficiently convincing that legislators in two dozen states introduced bills to prevent the spread of Islamic law, or sharia, and a Republican Presidential front-runner exclaimed, “I believe Shariah is a mortal threat to the survival of freedom in the United States and in the world as we know it”? This dissertation takes these puzzles as its object of inquiry. Using a framework that conceptualizes discourses and their agents as fundamentally political, this study deepens the literature’s characterizations of this discourse as “Islamophobia,” the “new Orientalism,” the “new McCarthyism,” and so on by examining how it functioned politically as a form of cultural politics, and how such political factors played a role in its expansion in the decade after 9/11. The approach is syncretic, blending Foucauldian genealogy with its emphasis on power, a more interpretive Bourdieuan relational sociology, and synthetic social movement theory. First, it examines the discourse at its macro-level, in the historical and structural factors that formed its conditions of emergence; specifically: 1) the culturally-resident political framing structure that rendered this discourse meaningful and credible; 2) the politically-relevant social-structural resources that rendered it influential; and 3) the more historically contingent or eventful political openings or opportunity “structure” that otherwise enabled, supported, or incentivized it. Then, it examines this threat discourse at its micro-level, biographically profiling three of its more influential polemicists, analyzing their strategies of cultural politics. The study concludes that this threat discourse functioned as a distinctive strategy by the more entrepreneurial segments of the U.S. conservative movement, who—in the emotion-laden wake of 9/11—seized Islam as another opportune site to advance their ongoing project of cultural politics. / Ph. D.