The conservative thinker behind Glenn Beck

What drives and inspires Fox News' one-man whirlwind of indignation, Glenn Beck? Well, according to American journalist Alexander Zaitchik, who is writing a distinctly unauthorised biography of the current hero of the American right, one of Beck's key political touchstones is the work of W Cleon Skousen, an ultra-right conspiracy theorist who was so extreme that he was disavowed – even hated - by members of the Republican party.

Skousen, who died in 2006 at the of 92, was a Mormon ideologue who spent his life fighting against the perceived threat to America of Soviet Communists and, of course, their fellow travellers in the American establishment. He founded the Salt Lake City-based National Center for Constitutional Studies and was a favourite of the anti-communist John Birch Society. However, though he boasted to J Edgar Hoover's FBI of his efforts to drive out communists, it turned out Hoover’s boys had amassed a 2,000-page folder on him.

Skousen’s legacy lives on in his books, such as The 5,000 Year Leap and The Making of America, both published in the early 1980s. The latter sparked a minor scandal when it was approved for use in California schools, despite its countless factual errors, descriptions of African-American children as "pickaninnies" and the somewhat controversial assertion that slave owners were the "worst victims" of the slavery system.

Beck's admiration for Skousen is no secret - the Fox News man wrote the foreword for a recent reprint of The 5,000 Year Leap - and some of the darker aspects of Skousen’s work have come to light in recent Beck rants, including some thinly disguised anti-semitism dressed up as art history.

On September 2, Beck (pictured) treated his viewers to an all-encompassing lecture in which he pointed out that the symbolism of artworks at the Rockefeller Center - coincidentally enough the HQ of Fox News's arch enemy NBC - not only displayed communist sympathies but also fascist ones.

Beck's unified theory of everything then brought in the UN building - constructed on land donated by the Rockefeller family - and concluded by linking the "progressive John D. Rockefeller Sr" to "communists and fascists".

As unhinged as Beck's rant appeared, the demonisation of such stalwarts of global commerce and banking as the Rockefellers and Rothschilds formed a key part of Skousen's warped world-view: his Freedom Institute was "devoted to the study of the super-conspiracy directed by the Rockefellers".

Flush with success at having dispatched Barack Obama's green czar, Van Jones, the prospect of an emboldened Beck using Skousen's works as a playbook for further assaults on the 'progressive' establishment has many American liberals up in arms. ·