I was too busy to repost this morning, but I would be remiss if I didn't bring people's attention to LK's post on the German Foreword. Of course this is something I've written on in the past too. This is something I would like to revisit again in the future - there's a ton of implicit German intellectual history in that foreword that gets obscured by the low quality analysis and simple demagoguery surrounding it.
LK makes an explicit comparison to some of the less savory things Mises has said about fascism. After providing the material, he writes: "If anyone is a candidate for having (in Rothbard’s words) a “strong fascist bent,” then it would be Mises, not Keynes."
I would put it this way - as far as I can tell, neither Keynes nor Mises were anywhere remotely in the neighborhood of sympathizing with fascism. However, I would say that if we found out that one of the two of them was a closet fascist or collaborated with fascists to reach other ends, I would be much less surprised to find out that it was Mises. The fact is, neither men were fascists - and that should be the take away. But Mises skirted the boundary in ways that Keynes never did. There is a pretty bold line between libertarianism and fascism. Libertarians are liberals, after all - and fascists are not. But insofar as libertarians tell a society they cannot make certain decisions for themselves and insofar as libertarians weaken the basic liberal institutions of representative democracy, they can make that bold line between liberalism and illiberalism fairly porous. This is a small, small minority, of course. I'm sure you all can think of one well known example of what I'm talking about. That's the sort of thing that worries me about libertarianism. But Mises the man was unequivocally a liberal - as was Keynes the man.
UPDATE: I want to be clear - just because I offered how I would have phrased it, and just because that emphasized that I don't think either are fascists - I didn't mean that to imply that LK thinks Mises was a fascist. He clearly doesn't.