The problem with conspiracy theories (well, one of the problems with conspiracy theories) is that they function as a playground for bigots. Theories like birtherism or 9-11 trutherism come to be popular in anti-Semitic and racist circles because they help to validate in the minds of these people that which they already believe to be true -- that the world's problems can be laid at the feet of ethnic group X or religion Y.

For someone like Glenn Beck, who tries (and fails) to walk the line between conspiracy theorism and legitimate history, encountering anti-Semitic cranks is unavoidable. This puts him in the somewhat comic situation of having to carefully weed out the bigoted aspects of already disreputable theories, and then trying to convince everyone that he's a historian, and not a lunatic.

Beck, it seems, isn't up to that challenge. Over the past few months, several anti-Semitic authors and theories have popped up in his TV and radio monologues, and Beck's audience of millions is, unwittingly or not, being exposed to some of the most hateful rhetoric of the last century.

On June 4, Beck took to the radio waves and told his audience all about this wonderful book he was reading called The Red Network: A 'Who's Who' and Handbook of Radicalism for Patriots. According to Beck, this book, from 1934, was proof that “McCarthy was absolutely right,” and evidence that even back before McCarthy went on his Red hunts, people in America shared Beck's concern about the communist infiltration of the country. “This is a book -- and I'm a getting a ton of these -- from people who were doing what we're doing now.”

As it turned out, The Red Network's author, Elizabeth Dilling, was one of the anti-communist movement's great anti-Semites. The book itself blamed “revolutionary Russian Jews” for the rise of anti-Semitic German fascism and called “racial intermixture” a communist plot. Dilling would go on to attend Nazi rallies in Germany and nickname Dwight Eisenhower “Ike the kike.” Beck was unapologetic, instead making himself the martyr, saying that “the left” was calling him “a Jew-loving Nazi sympathizer.”

On September 22, Beck went on Fox News and introduced his viewers to another book, called Secrets of the Federal Reserve, pulling a quote from it to attack Woodrow Wilson. The author of Secrets of the Federal Reserve was one Eustace Mullins, who passed away earlier this year. His obituary in his hometown paper began as follows: “Nationally known white supremacist and anti-Semite Eustace Mullins of Staunton, described in 2000 by the Southern Poverty Law Center as a one-man organization of hate, died Wednesday in Waller County, Texas, at age 86.”

Secrets of the Federal Reserve details the conspiracy of German Jewish bankers to seize the wealth of the United States through the Federal Reserve. Mullins led a prolific and well-documented life of anti-Semitism and conspiracy mongering, two themes that converged when he blamed the 9-11 attacks on the Israeli Mossad.

And just a couple of days ago, Beck went on a harangue against conservative boogeyman George Soros, hitting all the tired points that have become commonplace in the right's Soros fearmongering, but with a little twist. “He also rolled the dice in '97 in Asia and many, including the Malaysian prime minister, believe it was billionaire speculator George Soros who helped trigger the economic meltdown that spread through Malaysia, Indonesia, and the Philippines.”

Then-Malaysian prime minister Mahatir Mohamad told Forbes in September 1997 that he had “definite information” that Soros was “involved” in Southeast Asian currency speculation, and the following month told a Malaysian newspaper: “We do not want to say that this is a plot by the Jews, but in reality it is a Jew who triggered the currency plunge, and coincidentally Soros is a Jew. It is also a coincidence that the Malaysians are mostly Muslim.” As more and more evidence emerged directly contradicting his allegations of Soros' alleged misdeeds, Mahatir later conceded that Soros was “not involved in the devaluation of the Malaysian currency.”

That's three people with documented links to the poisonous world of anti-Semitism that Glenn Beck has approvingly cited in the last six months. And the evidence of their anti-Semitism was readily uncovered, requiring just a quick Google search -- something to keep in mind the next time Beck boasts of his research prowess.

Once is a fluke, twice is a coincidence, but three times...