the evidence that has been accumulated since Schumpeter's book gives good marks to free market systems in promoting the interests of the poor and middle classes, including minorities. And examples abound of corrupt and incompetent government officials who either mess things up for everyone, or promote these officials' interests. This evidence has impressed the man and woman in the street, but intellectuals are more removed from the real world, and tend to rely on and trust ideas and intellectual arguments.
This would be my primary explanation for the questions raised by Posner about why faculty (and I add other intellectuals too) have become further to the left of their students and the general population. In effect, intellectuals have changed their views far less than other groups in response to the evidence. While intellectual opinions have stood rather still, the general population has moved their thinking against government solutions and toward solutions that use markets and other private transactions and relations.
Bryan's reading of the evidence is that well-educated people are more likely than others to support free trade and markets in general.
But Caplan is talking about absolute levels of support, and Becker is talking about trends. And I agree with Becker about the trend in academia relative to the trend in the public at large.
As Alex Tabarrok's Bon Mot suggests, today it is the faculty who are inflexible. In fact, I argue that over the past 50 years, faculty have switched places with corporate CEO's in terms of intellectual flexibility.
In 1957, a typical CEO did not arrive at his view of the world through broad reading or keeping up with developments in the natural and social sciences. Instead, his (no need for a gender-neutral pronoun in 1957) opinions came from the prejudices of those within his narrow circle.
Today, that describes academia better than it describes corporate CEO's.
I should point out that I believe that Becker is too optimistic in his view of the general public. I do not think that pro-market sentiment runs particularly deep. True, people seem to have low trust levels in political leaders. But I do not see that stopping the politicians from expanding government's grip on health care, education, etc.
UPDATE: Lots more data and analysis of academic political views summarized here. The paper is here. Incidentally, I worry about people who self-describe as "moderates." That description depends a lot on context. I could describe myself as a moderate compared with Don Boudreaux or Bryan Caplan, but many people would regard my views as radical.