Since 2006, journalists, activists, and academics have produced a steady stream of books and articles warning of the dangers of Christian nationalism, which they define as "an ideology that idealizes and advocates for a fusion of American civic life with a particular type of Christian identity and culture" that "includes assumptions of nativism, white supremacy, patriarchy and heteronormativity, along with divine sanction for authoritarian control and militarism." According to sociologists Andrew Whitehead and Samuel Perry, 51.9 percent of Americans fully or partially embrace this toxic ideology.

These critics, Mark David Hall argues, greatly exaggerate the dangers of Christian nationalism. It does not, as they claim, pose an existential threat to American democracy or the Christian church in the United States. Who's Afraid of Christian Nationalism offers a more reasonable definition, measure, and critique of this ideology. In doing so, it shines important light on a debate characterized by unfounded claims, rhetorical excesses, and fearmongering.