Based solely on his remarks the other day, now enshrined forever on Youtube, I don’t think so. The man is a filmmaker, and it’s his job to get into the skin and soul of characters, in order to make stories. (I’m not a von Trier fan — Breaking The Waves and Dancer In The Dark were enough for me, I will probably never want to see Antichrist, and I don’t know anything about the new one. But that seems to be a matter of taste, and there are people who have the stomach to sit through the violence to see the film behind it. I’m just not one of them.)
I watched the video of the appearance and the comments he gave, and what I saw was a man trying to express a viewpoint that is probably shared by many a filmmaker or stage director, including the people responsible for Downfall (Der Untergang). You cannot portray evil successfully without finding some sympathy for the monster, in order to find out what makes the monster tick. Otherwise you’ve just got two-dimensional evil, which has no depth. Granted, he tried to say this through his strange sense of humor (he claims it’s a Danish one), and in a language he may not be comfortable with for such a topic, and I think he knew he was digging himself a pretty big hole as he tried to explain himself to the reporters present.
Politically dense — absolutely. An actual Nazi sympathizer — I doubt it. At least, not based on these comments.