He is referring to Alan Blinder, a member of the Council of Economic Advisers under President Clinton (Mankiw was Chairman of the Council under President Bush).
I once wrote that the Council of Economic Advisers should have a blog. Maybe we're getting there, although I'd say it's off to a rather awkward start.
Greg's point 3 is what I call a type M argument and what Jeffrey Friedman calls the "cynic's heuristic," which is to blame the other person's position on bad motives. Generally speaking, type M arguments should be avoided.
I also dislike Greg's point 2 about where Blinder chose to publish. I see that as gratuitously insulting and beside the point.
Interestingly enough, Blinder himself left a comment on Greg's blog in reply. I'll let him speak to points 1 and 4.
1. Out of the mainstream? Both my friend and former student and I teach introductory economics to some pretty smart students. With me, the first lesson on international trade is that (and why) there are gains from trade. (I love Ricardo!) The second is that trade always creates both winners and losers, though the nation as a whole gains. Don't Harvard students hear the second?
...4. Not persuasive? Well, persuasiveness is in the mind of the beholder. I clearly haven't persuaded Greg. But, then again, I never persuaded Milton Friedman to stop watching M2.
Mankiw is ticked off at a New York Times story in which a number of economists who have taken left-of-center positions whine about their treatment within the profession. It was a pretty shallow article, and I thought that Alex Tabarrok had the strongest response to it.
David Card, for example, says “You lose your ticket as a certified economist if you don’t say any kind of price regulation is bad and free trade is good.” Really? Card and Krueger's famous paper on the minimum wage was a 1993 NBER working paper published in the AER in 1994. What happened then in 1995? Was Card decertified, drummed out of the profession, vilified by his peers? Hardly, in 1995 David Card was honored (deservedly imho) by the American Economic Association with the John Bates Clark medal.
Even if Blinder and Card did not enjoy enviable rankings within the profession, it is unseemly to portray yourself as a victim because people disagree with you. If you run into critical headwinds, you need to do a better job of defending yourself on substance.
Ironically, Blinder's original article in Foreign Affairs strikes me as carefully hedged and downright bland. Where he and I would differ is that I think that the ability of government to devise a "solution" to the problem of future adjustments to the availability of educated labor from other countries is minimal compared to that of the decentralized trial-and-error groping mechanism of the market.