HOTEL BOHEMIA PRESENTS: "JOHNNY CARSON AND THE FANTASY OF AMERICA"- Narrated By Jason Zinoman-THE LATE NIGHT HOST LOOMS OVER OUR CULTURE TO THIS DAY- BUT THERE WAS A DARKNESS AT THE HEART OF HIS APPEAL

Maybe late-night TV shouldn’t be called “late-night TV” anymore, with so many viewers consuming it in clips the morning after, on their phones. Yet the genre’s hallmarks — the avuncular host, the sidekick, the band, the monologue, the desk, the guests — linger. Most were stamped on America’s consciousness by Johnny Carson. A new biography about an old reliable, Bill Zehme’s “Carson the Magnificent” harks back to an era when doom and scroll were biblical nouns and Carson’s “Tonight Show” was a clear punctuation mark to every 24-hour chunk of the workweek — less an exclamation point, maybe, than a drawn-out ellipsis. “They want to lie back and be amused and laugh and have a nice, pleasant and slightly … I hate the word risqué … let’s say adult end to the day,” is how a producer in 1971 described the millions tuning in from home, to Esquire. Carson went off the air in 1992, after three decades on “Tonight,” and left this Earth in 2005. Zehme, a journalist known for his chummy celebrity profiles, struck a book deal almost immediately but struggled to get purchase on his subject— “the ultimate Interior Man,” he despaired to a source, “large and lively only when on camera” — and then was diagnosed with late-stage cancer. He died himself last year at 64, and a former “legman” and friend, Mike Thomas, has finished the project, giving it a doubly valedictory feel. There were plenty of earlier books to consult, like “King of the Night,” by Laurence Leamer (who wrote about Joanne Carson in “Capote’s Women”), “And Now … Here’s Johnny,” by a young Nora Ephron, and the memoirs of Carson’s eternal second banana, Ed McMahon. His lawyer’s tell-all, published in 2013, is tellingly unmentioned. Zehme and Thomas have taken, if not the high road, the yellow brick one, with Carson’s Midwestern background left in dusty black and white while the nitty-gritty of show business is buffed to a high Emerald City sheen. Give the authors points for changing up the standard chronological format. We don’t get to Carson’s birth date of Oct. 23, 1925, in Corning, Iowa, until the 107th page; his rebirth on Oct. 1, 1962, in NBC’s Studio 6B, midwifed by Groucho Marx, being the main event. On air, Carson would take on various goofy guises, including the turbaned Carnac the Magnificent. The book’s title, and its light glide over his womanizing and sometimes violent alcoholism, suggest that in real life, too, he was a master of disguise and escape. After an unpleasant first date with Jody, he gives her a cactus in a bedpan with a note reading: “Sit on this. It will remind you.” After they married, she would sometimes wake with bruises. “Did he hurt you, Mom?” Joanna’s son asks after blowups. Zehme attributes such behavior to a booze-poisoned “doppelgänger”; he credits Carson with destigmatizing divorce without considering how swiftly, today, his whole operation would be canceled. Visiting a proto-couples counselor, Carson “would taste shrinkage for the first time,” but he was far more comfortable overseeing Carson’s Couch. He might have been his own best analyst. “My job is to give them that feeling,” he told the “Tonight Show” regular Tony Randall of his drowsing masses, “that there will be a tomorrow.” How very yesterday.