I've been following his work at a distance for some years now. He and his colleagues analyse real-world moral thinking based on "six clusters of moral concerns": "care/harm [eg., compassion for the underdog], fairness/cheating [here, distributive justice has a place], liberty/oppression, loyalty/betrayal, authority/subversion, and sanctity/degradation."
Among their findings: liberals and libertarians think almost exclusively in terms of the first three clusters. Social conservatives use all six, extensively. We liberals and libertarians, by comparison, live in a morally truncated world. At a fundamental conceptual level, their moral world is much richer.
The signs at Zucotti park, he finds, are extremely typical of the left-liberal Weltanschauung.
The most interesting thing in this particular article is the Machiavellian advice he offers OWS at the end:
[I]f the protesters continue to focus on the gross inequality of outcomes in America, they will get nowhere. There is no equality foundation. Fairness means proportionality, and if Americans generally think that the rich got rich by working harder or by providing goods and services that were valued in a free market, they won’t support redistributionist policies. But if the OWS protesters can better articulate their case that “the 1 percent” got its riches by cheating, rather than by providing something valuable, or that “the 1 percent” abuses its power and oppresses “the 99 percent,” then Occupy Wall Street will find itself standing on a very secure pair of moral foundations.When I read this I realized that, by George, equality is not to be found in his six "clusters." What you see is fairness, which (pace Rawls) is not the same thing. Haidt thinks of fairness as a matter of proportionality, not equality. Equality means treating everyone the same. Proportionality means treating people in appropriately different ways.
Then another realization hit me: if he is right, academic political philosophy is even more out of touch with the way normal people think than I had thought it was. Whether you look at Arneson or Cohen or Dworkin - or the vast horde of Rawlsians - it is pretty much wall-to-wall egalitarian. Their big issue is: which kind of eqalitarianism is the right one? The one thing they assume is the fundamental moral foundation for political thinking is something that most Americans, and possibly most human beings, don't really care about at all.