National Review, one of the conservative movement’s most celebrated publications, may be brought down by a smear it published against climate scientist Michael Mann. Mann’s lawsuit against the publication has already survived two challenges for dismissal and could exact a lethal toll on a media property that may already be losing money.

Mann alleges that one of National Review‘s writers defamed him by claiming his research was fraudulent and comparing him to convicted child molester Jerry Sandusky.

Climate scientist Michael Mann is suing National Review and Mark Steyn, one of its leading writers, for defamation. It’s a charge that’s notoriously hard to prove, which is no doubt why the magazine initially refused to apologize for an item on its blog in which Steyn accused Mann of fraud.

Steyn also quoted a line by another conservative writer (Rand Simberg) that called Mann “the Jerry Sandusky of climate science, except that instead of molesting children, he has molested and tortured data.” (Simberg and the free market think tank for which he works, the Competitive Enterprise Institute, are also named in the suit.)

The Sandusky comparison, while over the top, is not really defamation. It’s a nasty insult. But the claim that Mann committed fraud likely is. Steyn and National Review have yet to provide evidence that Mann committed fraud which would protect them. It’s not defamation if it’s true.

The lawsuit is continuing and if National Review is forced to settle or pay out damages it could be the end of the magazine.

Now, the lawsuit may well be dismissed down the road. But the longer it continues, the more likely it becomes that Mann will eventually prevail, either by forcing an expensive settlement or by prevailing in court and winning a substantial penalty from the defendants.

It’s doubtful that National Review could survive either outcome. Small magazines often lose money and only rarely manage to break even. They certainly don’t have substantial legal budgets, let alone cash to cover an expensive payout. Indeed, in 2005, Buckley said the magazine had lost $25 million over 50 years.

If National Review folds The Weekly Standard will become the dominant conservative magazine, at least as is measured by circulation. Whether that will mark any significant change in the conservative movement’s outlook on domestic or foreign policy is an open question.

National Review at one time represented the more sober and cerebral faction of the conservative movement, a movement dominated by reactionaries. Perhaps, given what the conservative movement has become with the Tea Party, the demise of National Review is appropriate. Now the conservative movement can go kicking and screaming into the dark rather than face its end with a little dignity.