My sister had a training with a tree sitting group in Montana, and as is the habit at such places, some angry young youths made a comment about fascists and the like. A trainer there, showing more academic rigor than might be expected, retorted that "fascism is an economic and political system, not a cop you don't like". While "fascism" is bandied about as an insult all then time, what it really means is not discussed much in American culture, perhaps because American culture has so far been spared the worst parts of fascism, or even proto-fascism.
The truth is that fascism is not primarily an economic or political system, but a religious and metaphysical system. Fascism as a metaphysical system posits a "base" nature of reality, given in its most basic formula as blood and soil. Fascism, in its most famous variants, as displayed in Japan, Germany, Italy and Spain, depended on a cult of unreflective worship of power, ethnic identity and action. In fact, it would not go too far to sum up fascism as a system of worship of the unreflective as such.
What does fascism have to do with liberalism? Although there are threads of modern liberalism in 18th century Republicanism and in religious movements such as the reforming Quakers of the 19th century, modern liberalism, meaning an attack on the concept of authority as such, a desire for ever greater equality amongst people, and an ongoing project of cultural reform, is a 20th century invention, dating back to the 1920s. Modern liberalism posits a pre-existing base, and then tries to break free of it. The roots of this intellectual tradition probably go back to Kant, and the awakening of most of the intelligentsia to the fact that there was an ever present break between the noumenea and the phenomenea: that is, no matter what category or system you tried to put human experience into, it would always break free, as the transcedent intellect realized that it was categorically different from the categories that could be communicated by society. The technicalities of Kant's philosophies had a very real impact, and continue to have a very real impact on how we think. In any case, the basic idea of liberal thought, as it has flourished over the past eighty years, is this: that whatever you identify as, something new, and different, is always better. And, in some cases, if this new and different thing was once thought to be bad or inferior, that is the best of all.
Liberalism could almost be characterized as the cult of total reflectivity, of always looking upon yourself from outside.
What is interesting then, is that liberalism and fascism, two systems of vastly different histories, and obvious pragmatic moral differences, share a common base: both posit a metaphysical base that is of the utmost sociological and psychological importance. The differences between them is that fascism teaches that the "natural" and "good" thing for people to do is to submerge and return to this undeniable base of blood and soil. Liberalism, on the other hand, gains its identity from a bid to refuse this identity, in a never ending quest to escape the ground below its feet.
What is interesting, and missed in this equation, is that liberalism wishes to reverse the metaphysical basis of fascism, without actually escaping it. Martin Heidegger, a philosopher (who incidentally may or may not have been a philosophical supporter of fascism), said that when Jean-Paul Sartre attempted to refuse Western metaphyics by saying that Existence preceeds essence, he simply reversed metaphysical terms without escaping them. It could almost be seen that liberalism is the politics of existence, of people making decisions as independent entities, while fascism is the politics of essence, insisting that people are no more than the carriers of a political and social order. And while liberalism reverses the equation, it can't truly break free of it.
If all of this seems very theoretical, it won't.