Varieties of criticism
Conservative criticism has nothing much to do with "left-wing" or "right-wing", because left-wing people are often very conservative, in the defined sense, while right-wing people can also be very radical, in the defined sense. The difference between "radical" and "conservative" has more to do with the belief in whether "a change to something genuinely new" is really possible and necessary. Radicals typically believe strongly that such change is highly desirable and necessary, and that it can be achieved. Their criticism is that there is "not enough" change. Conservative critics, by contrast, are very skeptical about any such change, because they feel the change is really "just another form" of something that already exists.
Christian right
The notion that conservative Christians want to reinstitute slavery and rule by genocide is not just crazy, it's downright dangerous. The most disturbing part of the "Harper's" cover story (the one by Chris Hedges) was the attempt to link Christian conservatives with Hitler and fascism. Once we acknowledge the similarity between conservative Christians and fascists, Hedges appears to suggest, we can confront Christian evil by setting aside 'the old polite rules of democracy.' So wild conspiracy theories and visions of genocide are really excuses for the Left to disregard the rules of democracy and defeat conservative Christians – by any means necessary.