In their e-mail rejection, they (NSTA) expressed concern that other "special interests" might ask to distribute materials, too; they said they didn't want to offer "political" endorsement of the film; and they saw "little, if any, benefit to NSTA or its members" in accepting the free DVDs.

Gore, however, is not running for office, and the film's theatrical run is long since over. As for classroom benefits, the movie has been enthusiastically endorsed by leading climate scientists worldwide, and is required viewing for all students in Norway and Sweden.

Still, maybe the NSTA just being extra cautious. But there was one more curious argument in the e-mail: Accepting the DVDs, they wrote, would place "unnecessary risk upon the [NSTA] capital campaign, especially certain targeted supporters." One of those supporters, it turns out, is the Exxon Mobil Corp.