What caused it?

Six months ago, Glenn Beck held his “Restoring Honor” rally on the National Mall, drawing a crowd of about 100,000. Newspapers and magazines featured the rally on front pages around the country. The next month, The New York Times Magazine devoted a cover story to him. “In record time,” the piece observed, “Beck has traveled the loop of curiosity to ratings bonanza to self-parody to sage.”

Just six months later, however, Beck seems to have traveled somewhere else entirely. His ratings and reputation are in steep decline: His show has lost more than one million viewers over the course of the past year, falling from an average of 2.9 million in January 2010 to 1.8 million in January 2011. He now ranks fifth among Fox’s six weekday talk hosts, trailing lesser-known personalities like Shepard Smith and Bret Baier. Beck’s three-hour radio show has been dropped in several major cities, including New York and Philadelphia, and has seen a ratings decline in most other markets. “It’s hard to gain a million viewers,” says Eric Boehlert, who follows Beck’s shows for the liberal media watchdog group Media Matters, “but it’s really hard to lose a million viewers.” And Beck’s fall contrasts with the fortunes of other Fox News hosts, like Bill O’Reilly and Sean Hannity, whose TV ratings stayed solid throughout 2010.

Beck’s commercial viability also seems to have suffered. His viewership among 25- to 54-year-olds, a prized advertising demographic, declined by almost one-half in 2010. An advertising boycott organized by liberal groups has caused over 300 companies—including Procter & Gamble, UPS, Coca-Cola, and Wal-Mart—to stop showing commercials during Beck’s show. The Beck brand isn’t what it used to be off the airwaves either: His most recent non-fiction book, Broke: The Plan to Restore Our Trust, Truth and Treasure, was his first book in eight years not to reach number one on The New York Times best-seller list.

Meanwhile, as a group, prominent conservatives have seemed more willing to speak out against Beck recently. Though some on the right always disparaged him—several profiles last year included anonymous Fox insiders criticizing Beck—almost none were willing to do so with their names attached. Recently, however, conservatives have been criticizing Beck openly. Bill O’Reilly, who feted him for an hour after the Restoring Honor rally, has rapidly become more and more dismissive. The Weekly Standard’s Bill Kristol has criticized Beck’s “rants about the caliphate taking over the Middle East.” Conservative Washington Post blogger Jennifer Rubin called Beck a “ranting extremist,” and former Bush administration staffer Pete Wehner wrote for Commentary’s website, “If conservatism were ever to hitch its wagon to this self-described rodeo clown, it would collapse as a movement.”

What happened? Beck built a following by making outlandish, conspiratorial claims—about ACORN, Obama, and so on. (Bizarrely, his extremism may have augmented the number of curious liberal viewers tuning in: A Pew Research Center poll from last September found that 9 percent of Beck’s Fox viewers identified as Democrats, and 21 percent as moderates or liberals.) But “anytime you have extreme stimulus,” says Alexander Zaitchik, author of the unauthorized Beck biography Common Nonsense, “you’ll have diminishing returns.” Beck, says Zaitchik, was caught “in a vicious circle”: To keep viewers coming back, he had to keep creating new, more intricate theories. Last November, in a two-part special that indirectly invoked anti-Semitism, he accused liberal Jewish financier George Soros of orchestrating the fall of foreign governments for financial gain. During the Egyptian Revolution, Beck sided with Hosni Mubarak, alleging that his fall was “controlled by the socialist communists and the Muslim Brotherhood.” Beck is now warning viewers not to use Google, accusing the search-engine giant of “being deep in bed with the government.” In recent months, it seems, Beck’s theories became so outlandish that even conservatives—both viewers and media personalities—were having a hard time stomaching them. Now, each new idea appears to be costing Beck both eyeballs and credibility. “At some point,” says Boehlert, “it doesn’t add up any more.”