From a reader:

It took me a while to figure it out, because at one time I was in touch with some fairly principled and knowledgeable local free-marketers and small-l libertarians, even one who ran a credible campaign for senator on the Libertarian ticket.
But a few years later a funny thing happened. The LP of Illinois started propagandizing on behalf of the genocidal Serbs. When I tried to resign (having just rejoined as a result of their getting onto the primary ballot) the party chair refused to take my name off the list and instructed me to get in touch and “work with” one of his henchmen until I saw it their way.
This was to include coming to my home so they could explain things they had already gone on at great length about in the newsletter. (Gist of the
argument: The genocide is a figment of people’s imagination and also the other side is doing the same thing too.) Apparently they saw no conflict between libertarian principles and their refusal to respect my decision about whom I would associate with. It took a rather more pointed e-mail on my part to convince them that I had no intention of ever communicating with them ever again or of rejoining the party until it repudiated and apologized for their stance. I think I complained to the national party but got either no response or “ain’t nothing we can do”. Ugh. And don’t even get me started about the hypocrisy of Ayn Rand.
So I took to calling myself a “P.J. O’Rourke Republican” or a “live-and-let-live conservative”. At present I will answer to either or both, since I consider them far less oxymoronic than “serious libertarian”.