Like Stanley, I’m a McWhorter fan. But the piece he highlights, published by The New Republic, is out there:

Jones was wrong, actually, in disavowing his support for 9/11 conspiracy theory. He signed the document, which can only mean that he supports the idea that 9/11 was planned, or that the Bushies knew something more than they have said, or at least that the charge is plausible enough to require investigation.
But support for that idea is hardly unknown among people of the left – and often gestural in its own way; look one of these types in the eye and ask “Do you really think George Bush and his cabinet engineered the murder of thousands and have kept the secret for eight years?” and watch the nervous pause and the look off into the distance. Speculations in this vein hardly meant that Jones was not sincerely committed to working within the government to do good.