American Taliban: How war, Sex, Sin, and Power Bind Jihadists and the Radical Right. The author is the founder of Daily Kos.
“Totalitarianism for Christ” is the phrase by Jeff Sharlet (NPR) he uses in the book that I think does capture the factual basis of why the right is a serious threat to democracy.
“Fact is, progressives hate the Taliban and other Islamic fundamentalists precisely for the same reason we hate rabid conservatives at home: their fear of change, their contempt for nontraditional lifestyles, their mania for militaristic solutions, and their fascistic efforts to impose their narrow worldview on the rest of society.” [intro p x]