So says Robert Tracinski, here:
Mann is attempting to install himself as a kind of American Lysenko. Trofim Lysenko was the Soviet scientist who ingratiated himself to Joseph Stalin and got his crackpot theories on genetics installed as official dogma, effectively killing the study of biology in the Soviet Union. Under Lysenko, the state had an established and official scientific doctrine, and you risked persecution if you questioned it. Mann's libel suit [against Mark Steyn] is an attempt to establish that same principle here.
Mann has recently declared himself to be both a scientist and a political activist. But in attempting to intimidate his critics and suppress free debate on global warming, he is violating the fundamental rules of both science and politics. If it is a sin to doubt, then there is no science. If it is a crime to dissent, then there is no politics.
