Everything is in its right place once again, with Jim Manzi, recently signed up to be The New Republic's "in-house critic" drawing fire from liberals. This situation is an improvement over the recent intramural dust-up at National Review, in which conservatives were after Manzi for attacking Mark Levin's climate change chapter in Liberty and Tyranny.
Manzi's crime this time is the same as it was in his run-in with Levin: criticizing faulty logic on climate change. He challenged, in his role as in-house critic, Al Gore's recent TNR article on climate change. His basic argument is that if you accept that anthropogenic global warming is a real phenomenon, it does not follow that proposed emission reduction policies such as cap and trade are advisable.
For his troubles, Manzi earned the labels of "right-wing misinformer" and "serial misinformer" from Joseph Romm, a brilliant and prolific environmental blogger, probably the most prominent one. Romm also accuses TNR of having "proudly hired Manzi to un-fact-check their articles" and in doing so "given a vote of no confidence to the articles that they do publish - and to the editorial team they assign to ensure the accuracy of that piece."
Now of course neither Romm nor any of the left-wing bloggers who have seconded his accusations can provide a single example of Manzi making a factual error or spreading misinformation, because he hasn't. In fact, if anything, Manzi's sin was precisely the opposite: challenging Romm's preconceptions about climate change policy without engaging in any distortions of the underlying science or even challenging the prevailing scientific findings, thereby denying Romm the easy out of writing Manzi off as a "denier" or crackpot. Romm's post contains a number of plausible objections to Manzi's thesis, but Manzi anticipated each of them in his post or addressed them previously. None are evidence that Manzi made any factual error.
If you have the time, look through Manzi's National Review archives or his American Scene posts to get a sense of his writing style. It's defined by transparency (he always links to sources for cited facts), straightforwardness (he shows every step and justifies every assumption), and deference. The last characteristic is perhaps the most notable, as Manzi will maintain cordiality with his interlocutors even after they accuse him of malfeasance. The one exception that I'm aware of is his infamous post on Levin's book -- which is actually the exception that proves the rule, because he later apologized for his tone and gave Levin the last word.
It seems as if it is because of Manzi's track record of being honest, open, and accommodating that Romm is unable to stand his arguments in a liberal publication without trying to undermine his credibility. It was for that same reason that many conservatives found Manzi's criticism of Levin so grating -- it's in a way easier to deny global warming altogether than to argue on Manzi's level. At the time, a number of liberals cast the reaction to Manzi-Levin as a sign that conservatives are close-minded, despite the fact that National Review did publish the piece, after all. But now that the tables have turned and Manzi is writing for TNR, some of the same liberal observers are questioning his motives and accusing him of "lowering the standard of discourse."
It is to National Review's credit that they published Manzi then, it is to TNR's credit that they publish him now despite the left-wing outcry, and it is to Manzi's credit that his soldiers on producing impeccably factual articles only to be derided as dishonest by both the right and left. If only the same could be said of Romm about his willingness to consider reasoned challenges to his assumptions.
(By the way, Romm's post originally contained a clear factual error: he cited someone who incorrectly claimed that Manzi was the CEO of Lotus (I can't find a cached version, but it's noted in a comment left in the morning). Since then Romm has fixed the error, but there is nothing in the post indicating that it has been changed. A meaningless mistake, but suffice it to say that the "misinformer" Manzi would not make a factual error and then fail to acknowledge it in the post.)