Huntington's clash theory targeted all of Islam, not just extremists. [fact]
Huntington's clash of civilizations theory did not narrowly pit the United States against "Islamic fundamentalism" or "Middle Eastern terrorists." Rather, the clash Huntington theorized was against the whole of Islam, a faith practiced by 1.7 billion people, millions of them in the United States. Like his Orientalist predecessors, Huntington viewed Islam as a malignant monolith, writing that "Islam's borders are bloody and so are its innards." In the same way that Europeans and Americans invented the Orient, Huntington constructed an "Islamic civilization" that was based on essentialist myths, arcane stereotypes, and most absurdly, a homogenization of a supremely diverse region.
XREF: Connects to Edward Said's Orientalism and the critique of essentializing Islam as a monolith, which the author explicitly invokes.
Khaled A. Beydoun, American Islamophobia_ Unde…, loc. 228