Jimmy Fallon Was on Top of the World. Then Came Trump.

May 17, 2017, 05:00 PM

Ambling onto the Art Deco set of “The Tonight Show” for his monologue rehearsal one Monday afternoon, Jimmy Fallon gave the crowd here at Studio 6B a warm, practiced welcome before trying out a new batch of jokes about the French election, the pop star Harry Styles and President Trump’s definitions of medical terms. “He thinks a cardiologist is someone who works at Hallmark,” he quipped.

Wearing casual clothes and a boyish smirk, Mr. Fallon made a pitch for his program’s vision. “Anything I can make fun of, I will make fun of,” he told his audience. The late-night entertainment being fine-tuned in front of them, he added, had been devised so that “you go to bed with a smile on your face and you have sweet dreams.”

Then he stepped to the spot where he delivers his monologue each evening and noted that the stage mark was in the shape of a four-leaf clover. “I’m Irish,” he explained, “and I need all the luck I can get.”

It was a throwaway, self-deprecating line, but also an accurate self-assessment from Mr. Fallon, 42, who is in his fourth year of hosting “The Tonight Show,” NBC’s flagship late-night program.

He is weathering the most tumultuous period in his tenure there — a predicament for which he has himself to thank, and one that raises the question of whether the multitalented but apolitical Mr. Fallon can ride out the current era of politicized, choose-your-side entertainment, when he just wants to have a good time.

Once the undisputed juggernaut of the late-night category, Mr. Fallon’s “Tonight Show,” a celebrity-friendly cavalcade of games and gags, has seen its ratings decline in recent months. Meanwhile, his politically pointed competitor Stephen Colbert, who hosts CBS’s “The Late Show,” has closed what was once a formidable gap of nearly one million viewers.

The resurgent interest in left-leaning programming hasn’t helped Mr. Fallon, a former star of “Saturday Night Live” who has built his brand on his all-around entertainer’s skills and down-the-middle tastes. And as Mr. Fallon is well aware, viewers haven’t seen him in quite the same light since an interview he conducted with Mr. Trump in September, which was widely criticized for its fawning, forgiving tone. In a gesture that has come to haunt the host, he concluded the segment by playfully running his fingers through Mr. Trump’s hair.

But when the backlash did not subside, even after a few days, Mr. Fallon never addressed the controversy on air. “I didn’t talk about it, and I should have talked about it,” he said. “I regret that.”

One event after another seemed to intervene in Mr. Fallon’s life, crowding out the fury over the Trump interview but not quelling it.

In October, The New York Post published an article that claimed NBC was concerned with Mr. Fallon’s drinking, a charge he categorically denies.

“I could never do a day-to-day job if I was drinking every night,” he said. “That’s just kicking you when you’re down.”

Mr. Fallon acknowledges now that the Trump interview was a setback, if not quite a mistake, and he has absorbed at least a portion of the anger that was directed at him by critics and online detractors.

“They have a right to be mad,” a chastened Mr. Fallon said in an interview this month. “If I let anyone down, it hurt my feelings that they didn’t like it. I got it.”

But if these events prompted Mr. Fallon to search his own soul, he said they did not compel him to make widespread changes at “The Tonight Show.”

The program is still profitable and strongly supported by advertisers, so if Mr. Fallon faces any crisis, it’s an existential one: What if the broader shift to a more partisan, more openly anti-Trump late-night isn’t temporary? If it has a longer life and a bigger impact than anyone foresees, what does he want his show to be?

As strongly as ever, Mr. Fallon believes it should be a place for a wide swath of viewers to get their entertainment and laughs, and that this philosophy will steer it through a period of intense polar...