|If libertarians are concerned to protect the freedom of all, and not just the freedom of most, we will want some mechanism that catches those who fall through the cracks left by imperfect market competition. We will want, too, some mechanism for protecting individuals whose economic vulnerability renders them vulnerable to domination outside the marketplace – the woman, for example, who stays with her abusive husband because she lacks the financial resources to support herself without him.|
We might want a mechanism to keep people from being vulnerable, but that isn't a matter of insuring their freedom. Being poor, or facing a difficult market situation for your labor skills or anything you have to sell, isn't an infringement on your freedom however undesirable the situation may be.
The libertarian case for a basic income is no so much the case for a basic income full stop, but the case for a basic income as opposed to all the other welfare (and possibly other non-welfare transfer) programs.