Not to open the can of worms, but IMHO "American exceptionalism" is the only "ideology" with the potential  to underpin a totalitarian regime in the US. Every other single ideology appeals to too small a fraction of the population, and American exceptionalism permeates even civics classes in school.

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman