Glenn Beck, the conservative television and radio host, is an amateur historian. Very amateur.

One day, he rhetorically asked his Fox News viewers: "Why did we buy Alaska in the 1950s?" A good question -- because "we" purchased Alaska in 1867. Another day, he gave his version of European history: "We have the Age of Enlightenment, 1620 to 1871, uh, 1781. This was a time when people said, 'Wait a minute, wait a minute, we can think out of the box.' This is coming out of the Dark Ages." That was thinking outside of the box, because the Dark Ages ended in about 1000 AD, six centuries earlier than Beck claimed.

Beck has created an online "Beck University" to spread his unique views of the past and has hosted "Founders' Fridays" on his television show, devoted to rewriting the nation's early history as that of a fundamentalist state.

When the subject turns, as it usually does, to President Obama, Beck again sees lessons from history. In particular, he has seized upon two individuals who he believes provide excellent historical parallels to the 44th commander in chief: Woodrow Wilson and Adolf Hitler.

You don't understand how Obama is tied to a genocidal monster and to an American president who died 86 years ago? Allow Professor Beck to explain.

On Aug. 11, 2009, in the middle of a summer of rage-filled town hall meetings over health care, Beck said he would describe some Obama administration plans that "should horrify America . . . particularly if you're elderly, handicapped or have a very, very young child." And with that, the lesson began.

American "progressives" such as Wilson, Beck explained, were responsible for inspiring "the Nazi eugenic idea [which] evolved naturally into the eventual Holocaust and the deaths of 6 million Jews." He went on: "The builder of the master race was only part of the problem in Germany, made possible after they began to devalue life. They tried to figure out how much is a life worth, and put a price on how much each individual was worth -- and some were worth more than others."

Naturally, this led straight to Obama. Beck explained -- without benefit of actual fact -- that Obama's advisers favor health-care rationing and sterilants in drinking water, and then he went on to endorse Sarah Palin's allegations that Americans would have to stand before Obama's "death panel" so bureaucrats could decide who was worthy to live.

Voila! We go from Hitler's eugenics to Obama's health-care plan, with an assist from poor Woodrow Wilson.

Telling the nation that Obama is leading the country into Nazism is outrageous -- and that's exactly why Beck has been so successful. He averages more than 2 million nightly viewers on his Fox show, brings in $32 million in annual revenue from his various ventures, according to Forbes magazine, and is an unofficial leader of the tea party and its mass anti-government rallies.

Beck has achieved this in part because he is willing to do what other leading right-wing talkers are not: "to give a platform to the conspiracy theorists and anti-government extremists," as the Anti-Defamation League puts it. His fellow Fox News host Bill O'Reilly once said Beck succeeds because he is willing to "take it five steps further than I do."

At the heart of Beck's technique of amplifying fringe theories is his obsession with Nazism. For much of the past 70 years, there has been an unwritten rule in U.S. political debate: Avoid Hitler accusations. Once you liken your opponent to the Nazis, any form of rational discussion becomes impossible. But Beck, it seems, has a Nazi fetish. In his first 18 months on Fox News, from early 2009 through the middle of this year, he and his guests invoked Hitler 147 times. Nazis, an additional 202 times. Fascism or fascists, 193 times. The Holocaust got 76 mentions, and Joseph Goebbels got 24.