On January 19, 2009, the first episode of Glenn Beck aired on Fox News. Sitting at a desk in a brightly lit studio, Beck read off the day's headlines and transitioned from one discrete segment to the next: the “Hot List,” the “One Thing,” etc. He discussed the economy with Ben Stein and Obama's inauguration with Karl Rove. The second half of the show was eaten up by interviews with Sarah Palin and the wives of border patrol agents. Beck had big-name sponsors, and his overall tone was hopeful: “I've been thinking, what is the message that I want to bring? And it is -- we're in tough times but we're going to make it, if we count on each other, if we become 'we, the people' again.”

In short, it was a standard-issue conservative opinion program with Beck's unique touches.

Fast forward two and a half years, to the June 15, 2011, episode of Glenn Beck. Standing in a darkened studio surrounded by chalkboards, Beck warned that George Soros was involved in the “final collapse” of Greece. He insisted that the Three-Fifths Compromise was designed to “help free slaves.” After warning that “violence” might soon be “coming to America,” Beck theorized that postal workers would be armed and made part of a nefarious “civilian force” that would rival the military. There were no guests (save for one of Beck's radio co-hosts pretending to be a founding father) and no discrete segments. Just Beck, standing in front of his chalkboards, delivering an extended monologue that was periodically interrupted by ads for survival seeds and shady gold sellers.

The differences are stark -- not just in the tone and content, but in the format of the show. When he started out on Fox, Beck's program dealt in the day's politics and was a prime venue for GOP officials and conservative pundits and academics to get some cable news face time. But as the show progressed, Beck's rhetoric became darker and more extreme, and he became increasingly isolated. He went from discussing electoral politics with Karl Rove to warning of a biblically prophesied Islamic-socialist caliphate threatening to undo Western civilization.

In an early promo for his Fox News program, Beck claimed to disavow those on the “right” who talk about progressives and Democrats “trying to turn us into communist Russia.” His high-minded commitment to eschew red-baiting proved short-lived, as Beck accused President Obama of being a socialist who “surrounded himself with Marxists his whole life,” and launched a segment called the “Comrade Update,” in which he played the tongue-in-cheek part of an insider to the communist scheme to destroy Western civilization.

As 2009 progressed and right-wing anger at Obama steadily increased and mutated, Beck's show became a platform for prominent conservatives to take shots at the president. Rep. Michele Bachmann (R-MN) appeared on Beck's program to promote the anti-census movement, of which she was the de facto leader. He teamed up with Andrew Breitbart and James O'Keefe to release the fraudulent ACORN videotapes. Even Rush Limbaugh, who is peerless among right-wing commentators in terms of reach and influence, called into Beck's program to spout his distinctive brand of anti-Obama vitriol. Summer 2009 also saw the beginning of Beck's “In A Nutshell” segments and his habit of spotting "connections" between progressive groups that, he claimed, everyone else the in the media were missing.

Most important, though, was Beck's decision to start attacking Obama over racial issues, which led to the defining moment of his Fox News career: His attack on Obama as a “racist” with a “deep-seated hatred for white people or the white culture.” That moment sparked the advertiser boycott of his show, which reportedly cost Fox News millions of dollars in ad sales.

Beck, in the meanwhile, kept updating his shtick and sinking deeper into conspiracy theorism. He started using the now-famous chalkboards and began talking about the "Tree of Revolution." Beck's rhetoric also became increasingly violent; he said the Obama administration was “putting a gun to America's head” and wielded a baseball bat as he warned that “you too could be the next victim of the killing spree.” More often than not, the talk of violence and conspiracy mongering were accompanied by attacks on the Tides Foundation, which Beck often placed at the center of his chalkboard diagrams.

After spending most of 2009 warning, sometimes literally, that the end of America was nigh, Beck kicked off 2010 by promoting himself as the person who would “restore honor” to the country. But even as he imagined for himself a grander and grander role among the pantheon of American heroes, his Fox News colleagues were starting to view him as a problem. In a March 2010 Washington Post column, Howard Kurtz reported that “Beck has become a constant topic of conversation among Fox journalists, some of whom say they believe he uses distorted or inflammatory rhetoric that undermines their credibility.” Kurtz's article prompted Fox News chairman Roger Ailes to warn employees off intramural sniping: “Glenn Beck, does his show and that's his opinion. It's not the opinion of FOX News and he has a right to say it.”

Not long after Ailes defended Beck's right to voice his opinion, the real impact of Beck's rhetoric -- specifically his continued, unfounded smears of the Tides Foundation -- was realized on a California highway as Byron Williams was stopped by the highway patrol and opened fire on the police officers. Williams told police afterwards that he had intended to kill people at the Tides Foundation and the ACLU, and credited Beck with “exposing” information that “blew my mind.”

Nevertheless, Beck continued to enjoy significant clout leading into his “Restoring Honor” rally in Washington, DC in late August 2010, which featured Sarah Palin and Republican members of Congress among the featured guests. Beck had spent months promoting the event on Fox News and casting himself as a modern-day Martin Luther King, Jr. He also framed the rally in explicitly religious terms, telling attendees to expect “miracles” and prefacing the actual event with a religious rally at the Kennedy Center.

The overt religiosity of “Restoring Honor” continued to permeate Beck's show as he mixed wild conspiracy with apocalyptic rhetoric, recasting (relatively) mundane political squabbling as epic battles between good and evil and putting himself in the same category as biblical leaders. He also began promoting religious extremists and fringe academics, some of whom were ardent anti-Semites. And Beck himself began trafficking in anti-Semitic rhetoric in his relentless attacks on George Soros, calling him a "puppet master" who controls the media, and falsely accusing the billionaire financier of collaborating with the Nazis.

Neither condemnations from Jewish groups nor the ongoing advertiser boycott did anything to change Beck's behavior -- he instead boasted that he was still on the air despite what he claimed was a campaign against him orchestrated by -- who else? -- George Soros.

Beck's ratings, however, were declining rapidly, and his increasingly eccentric behavior was alienating more and more people at Fox News, including Ailes. The New York Times's Mark Leibovich reported in October 2010 that Ailes was increasingly upset with Beck's use of Fox News' airwaves to promote his own ventures. Leibovich also noted: “When I mentioned Beck's name to several Fox reporters, personalities and staff members, it reliably elicited either a sigh or an eye roll. Several Fox News journalists have complained that Beck's antics are embarrassing Fox, that his inflammatory rhetoric makes it difficult for the network to present itself as a legitimate news outlet.” At the time, Beck's ratings were down about 30 percent from 2009.

The beginning of 2011 saw the conservative establishment finally turn on Beck and his increasingly extreme brand of conspiracy theorism. After Egyptian leader Hosni Mubarak was deposed, Beck claimed that the revolution in Egypt and unrest in other North African countries were the first steps towards the establishment of an Islamic caliphate that, with the help of communists and socialists, threatened to engulf the Middle East, North Africa, and even Europe. William Kristol of the Weekly Standard deemed this “hysteria” and likened Beck's fearmongering to that of the John Birch Society. The National Review's Rich Lowry slammed Beck's “wild theorizing,” and Wall Street Journal columnist John Fund criticized Beck's “apocalyptic conspiracy terms about America becoming an Islamic state -- that goes too far.” Andrew Breitbart, who had collaborated with Beck on the ACORN tapes, also turned on Beck, claiming that Beck had thrown him “under the bus” on the Shirley Sherrod story.

Beck, in response, lashed out at Kristol and others and angrily insisted that not only was he right about the “caliphate,” but that his warnings of the coming destabilization were informed by a “gift” of “being able to see slightly over the horizon.”

By the time Fox News announced in April that Beck's show was ending, it barely resembled the program as it began in 2009. Beck's first Fox News show was a comparatively tame, even hopeful assessment of America's future. By contrast, on his April 6, 2011, program -- the day he confirmed his planned exit from Fox News -- Beck suggested that there was some sort of connection between the unrest in North Africa, earthquakes in Japan, and a Soros-convened meeting in the U.S. The next day he described Iran's relationships with Russia and Turkey as the fulfillment of a prophecy from Revelation: “This is the alliance of Gog and Magog.”

In two and a half years, Beck's Fox News show went from went from Karl Rove and Sarah Palin, to Gog and Magog. And that provides a tidy explanation for how Beck went so rapidly from Fox News ratings phenom to right-wing pariah and outcast.