I don’t have a ton to say on the subject of Ayn Rand, but I think the right answer to the question Kevin Drum asks here is that you have to understand Rand primarily as part of the intellectual backlash to 1950s comformism. Even though her specific political views were quite different, she should be seen as a peer of the beatniks and similar movements. That’s part of the reason why if you look at the fact that the main way her intellectual influence works is as a writer who appeals to young people. I know very few people who are Randians today, but a great many people who loved Rand as a teenager and for whom she served as a “gateway drug” to the much more sophisticated arguments of Nozick, Hayek, Friedman, etc.
Anyone who’s sitting around as an adult and actually taking their political cues from Atlas Shrugged is being ridiculous (and there are indeed a lot of ridiculous people out there adhering to all kinds of political viewpoints) but I think you need to see at first and foremost as part of the literature of youth rebellion.