“Two years ago, I was on a cable channel that no one was watching at the time, doing a show that no one was watching, and I was about to leave television. And then I had the opportunity to come and work here,” he said. “If you’re going to do news or commentary, the only place, I think in the world, the only place that really makes an impact is Fox.”

William Kristol of The Weekly Standard suggested that Mr. Beck is “marginalizing himself” by arguing that socialists and leftists were working with Islamic radicals to sow worldwide chaos. But Mr. Beck has always marched to his own idiosyncratic music, and his ratings actually began dropping long before Egypt rose up against its leader.

The problem with “Glenn Beck” is that it has turned into a serial doomsday machine that’s a bummer to watch.

Mr. Beck, a more gifted entertainer than most cable hosts, can still bring it, lighting up with characters and voices. But much of the time, there is sense that the fatigue from always being on alert, tilting forward in the saddle against the next menace, is starting to wear him down.

What had been a fast and loose assault on all things liberal has grown darker and less entertaining, especially with the growing revolution in the Middle East, a phenomenon Mr. Beck sees as something of a beginning to some kind of end. He’s often alone in the studio with his chalkboards and obscure factoids, a setting that reminds me of an undergrad seminar on macroeconomics with an around-the-bend professor I didn’t particularly enjoy.

Last Wednesday, as he grabbed all the disparate strands from around the globe and tied them into a great, grand bow of doom, he ambled alone between various blackboards, each jammed with portentous bullet points. He often looked away from the camera into a middle distance as he spoke of a calamity that only he can see.

“He used to be a lot funnier,” said David Von Drehle, who wrote the article in Time magazine. “He was the befuddled everyman and something entirely new, but the longer people have listened to his ranting and raving, the wearier they become. Now you are just getting down to diehards. I mean, how many people were in the Waco compound at the end? A couple of hundred?”