A book recommendation: Jonah Goldberg's Liberal Fascism: The Secret History of the American Left, From Mussolini to the Politics of Meaning.
I've been reading this book off and on since it was published in early 2008. It rested among my stored books for four years and now sits on my nightstand. It's not at all what you might think.
Basically, Goldberg argues that the Left in American politics is a "kinder, gentler" form of European fascism. He delves into the history of the movement, starting with Mussolini, and marks out how fascism is a thoroughly leftist ideology.
He also traces the history of how fascism became associated with the political Right in the U.S. He quotes liberally from 1930's fascist propaganda, noting that many American Leftists at the same praised Mussolini and Hitler for their forward-looking grasp on economics and social engineering.
He's quick to say that he's not claiming that American Leftists are Nazi's, etc. But he does draw some frightening parallels between fascistic "mass movements" in pre-WWII Europe and the student movements of the 1960's and current "identity movements" on contemporary campuses.
I'm not a political philosopher or historian, so I can't judge the truthfulness of his claims in these areas. I can tell you that as a reformed Leftist, many of his claims about the "politics of meaning" and "identity politics" are spot on.