If ethics is about the virtuous man then politics is about the social requirements for the virtuous man to exist (the modern literature lags behind Rand in connecting ethics and politics). One can understand Rand’s novels as an extended disquisition on virtue ethics and the political and social requirements necessary to practice such an ethics. In particular, she argued that rights, a legal concept creating a protected sphere for independent action, were a necessary condition to live a life of virtue.
One need not buy Rand’s deductive argument that laissez-faire capitalism is the sine-qua-non of ethical action to appreciate her insights connecting the good man and good woman with the good society. Ayn Rand was absolutely right to say that capitalism requires a moral defense. Moreover, the only plausible defense must involve the virtue of selfishness. It is all too obvious that capitalism promotes and rewards self-interest and, Mandeville nothwithstanding, no defense which simply excuses this fact will succeed.
Rand’s language hasn’t done much to advance her case and indeed it has obscured areas where her insights are now widely accepted. Today, for example, you can find many books
attacking the evil of altruism. Surprised? Of course, the books don’t use those terms, instead they call it the problem of codependency (or some other such). Relatedly, it’s no accident that Hillary Clinton was once an avid Randian (recall her political career started with Barry Goldwater) because Rand is an important feminist. Rand’s portrayal of strong, independent, intelligent women is coming to be recognized as a landmark in fiction but in addition Rand’s attacks on self-sacrifice have special meaning in a culture that has long used the “caring ethic” to bind women to the service of others.
Of weaknesses there are many, most of which flow from the combination of Rand as philosopher, novelist and powerful personality. John Galt, for example, is but one instantiation of the Randian/Aristotelian virtue ethic, an instantiation which was created for a particular aesthetic purpose by a particular person. To often both Rand and her detractors have taken the instantiation for the class thereby limiting the vision.