The Guardian article makes sense out of the whole mess. That Klein quote was in all the reports, but this one goes into a lot of detail about his hate-mongering career and the role he had in making the film, too long and complex even to summarize here. Thanks, McGrath, for that link.

The only question that remains is why the US government allows those hate groups to flourish. The standard answer is to wring our hands and say it's a shame we can't prevent things like this, but it's because we value freedom, and the only way to prevent it would be by taking away that freedom. That myth persists even now, when we can't get on an airplane with a bottle of water, and the President can have any one of us pulled out of our home and sent to a cage in Guantanamo without giving a reason.