Sometimes a comment on Econlog is so valuable that I think it needs to be highlighted. Most of the people I talk to who read this site regularly but who don't comment, don't read others' comments either. They would miss, therefore, David Friedman's cogent comment on Bryan Caplan's recent post.
I agree that it is worth pointing out that government hurts the poor, and also worth disagreeing without being disagreeable. But I don't think either of those positions represents the difference between Bleeding-heart libertarians and other libertarians. I offered arguments for open immigration and reasons to think that government often hurts the poor in a book published about forty years ago--and neither of those was an exotic position among libertarians then.
My complaint about the BHL, as may be obvious from the exchanges now going on, is that they insist that social justice ought to be part of libertarianism but are unwilling to tell us what it means. As far as I can judge by observations of usage, "social justice" means "ideas of justice that appeal to left wingers," and its practical implication is the rule that, with regard to any issue at all, the first question to ask is how it affects the poor.
The only reason I can see why libertarians would want to adopt that terminology is to appeal to leftish academics. Fraudulently.
I have known David since November 1971 and I know how thoughtful he is about things. I also know how carefully he states things. Notice that he's NOT saying that arguments about focusing on the poor are bad arguments. He (and I) think they are powerful arguments.
I would love to see how the BHLs respond to his Reaction Essay of April 6, 2012. Maybe they have and I've missed it. Cato Unbound puts up an essay without giving a link or even hinting that there's another essay on the same topic, except the essay on which the author is commenting. So if anyone can point me to an essay where Matt Zwolinski and/or John Tomasi explicitly address David Friedman's points, I would appreciate it.