Goodbye to the big blackboard. Goodbye to the turn-it-on tears. Goodbye, too, to the suppertime serving of anger, conspiracy and the coming apocalypse.

Glenn Beck — populist ranter, Barack Obama scourge, self-described “rodeo clown” — stepped away from his biggest stage Thursday. After a volcanic rise and a muddled denouement lasting just 30 tumultuous months, the host ended his run on the Fox News Channel, going out with what sounded almost like a threat: “For those members of media who are celebrating [his departure] . . . you will pray for the time I was only on the air for one hour a day.”

Beck’s Fox finale was a vintage visit to what he once referred to as the “doom room.” Like a teacher reviewing his lessons before the final, he offered viewers a last look at “Things We’ve Learned” — a synopsis of fear — on his ever-present blackboard. On the lengthy list: the Fed, Woodrow Wilson, ACORN, the caliphate.

“We have taught things and learned things together that we never knew,” he said. “We’ve learned a lot together. . . . We’ve done amazing things together.”

There were no tears, but there was plenty of sentimentality and self-congratulation. Beck thanked his production crew and his viewers, as well as Fox News chief Roger Ailes and Ailes’s boss, News Corp. chief Rupert Murdoch.

Beck suggested that his departure was his own call, planned many months ago, but even Ailes has muddied those waters. Given Beck’s declining ratings and growing radioactivity among advertisers, the network has left it unclear whether Beck jumped or was pushed. “Half of the headlines say he’s been canceled,” Ailes told the Associated Press in April. “The other half say he quit. We’re pretty happy with both of them.”

At his peak last year, Beck’s audience at 5 p.m. — nearly 3 million — exceeded the combined viewing of all his time slot competitors in cable news. It also rivaled that of cable news’s leading prime-time attraction, Fox’s Bill O’Reilly. Beck once rated the cover of Time magazine, which headlined its article “Mad Man,” and asked a provocative question: “Is Glenn Beck Bad for America?”

More than one commentator has noted that Beck’s rapid rise reflected acute anxiety over the financial crisis and recession. Equally so, Beck’s fade-out might mirror the softening of the crisis or just weary acceptance of it.

Nevertheless, Beck isn’t generating the heat he once did. He has lately struggled to attract half as many viewers as in the past.

As a conservative political polemicist and clarion of anti-Obama rage, Beck, 47, often danced near the edge of reason and sometimes tumbled madly over it. On Fox, he mixed messages of self-empowerment, patriotism and religious appeals with recycled theories about a conspiracy to impose a New World Order.

Appearing on Fox News’s morning show in mid-2009, he asserted that Obama was a “racist” who harbors “a deep-seated hatred for white people.”

He has variously described Obama as a Marxist, a socialist and a fascist.

In November, Beck launched a three-part attack on billionaire philanthropist and Democratic Party contributor George Soros as the “puppet master” of a global plot to subvert governments, including the United States. The programs included Beck’s baseless assertion that Soros had been a Nazi collaborator as an orphaned 14-year-old in his native country, Hungary.

Confronted repeatedly with stunned and outraged reactions to Beck, Fox remained officially silent and at times came to his defense. After Beck’s Obama-is-a-racist outburst, a Fox news executive said the opinions were Beck’s, not the network’s, “and as with all commentators in the cable news arena, he is given the freedom to express his opinions.” It was about as close to contrition for Beck’s broadsides as Fox came.

A gifted monologist and showman, Beck’s entertainment instincts were sharpened by years as a Top 40 DJ, including on Washington’s WPGC (95.5 FM), and morning “zoo” host. (Some of the nation’s most popular radio talkers, including the godfather, Rush Limbaugh, learned how to work a microphone the same way). Beck was one of the few hosts to successfully translate the incendiary rhetoric and daily gripes of talk radio into a successful TV run.

Far from disappearing, Beck will carry on across the multimedia spectrum with a nationally syndicated radio program, best-selling books, a magazine, a Web site and massively attended personal appearances, such as his “Restoring Honor” rally in Washington last summer and a coming one in Jerusalem.

His next project is a subscription-based daily webcast, (slogan: “The truth lives here”), which Beck began moments after his TV sign-off. Fox also has said he would collaborate on “a slate of projects,” although none have been disclosed.

“I didn’t run away from something,” he said during his swan song Thursday. “I’m running to something. I know exactly where I’m going.”

He didn’t mention what. Or where.