Her goal is noble--to point out how dangerous the encroachments on personal liberties and the consolidation of authoritarian power can be, and to point out instances where the US is doing those things. That's all great. Her argument that we are inevitably trending towards a de facto fascist state comparable to some of the worst in recent history is, however, totally bogus. And it runs into the same problem I love to blast people (including myself!) for over and over again. I describe my issues with inattentive or hasty historical comparison at length
here.
Why are her comparisons bogus? Because to make comparisons between two very different situations, she has to ignore such major differences that her comparisons lose meaning, and lose effectiveness as predictors of actual fascism. When you ignore the totality in favor of a few pleasing similarities for the purpose of making a point, you can forget that the two compared entities have crucial, epochal differences. For example, Guantanamo is a gulag by definition, but does it have the -magnitude- of prisons in Nazi Germany or Soviet Russia? Is it used to the same extent and for the same reasons? Nope. Therefore comparing the two deprives each of its context, and the comparison loses meaning and approaches invalidity.
An easy way to point out the flaws of these facile comparisons is that America under FDR or Lincoln each qualify as having the same indicators she describes as "the End of America."
Invoke a terrifying internal and external threat? Check. Prison camps for political dissidents or undesirables that neglect human rights? Check. "Thug class" or vigilante nationalistic gangs attacking these undesirables? You bet. Internal surveillance? Sure (though almost every modern industrialized nation has a form of this--again it comes down to method and magnitude). Media control? Arbitrary detention? Unconstitutional crushing of dissent? Suspension of the rule of law? All factors in those two past Americas.
Did it lead to fascism in either case? Nope. -That's- why you have to pay attention to specifics, and identify major contextual and individual differences. Now, as to whether Wolf's book is a bad thing, I'd say in general its aim is very noble. These -are- dangerous attacks on civil liberties, and an encroaching authoritarian state is something to argue against whenever possible. However, I think she is using some very disingenuous arguments to promote that idea. That's fine to do as an activist, as rhetorical marketing tricks are naturally part of the trade, but let's not pretend such is a wholly honest and empirically valid argument. Because it's not.