In George Clooney’s brief, conspicuously modest playbill bio for “Good Night, and Good Luck,” the two-time Oscar winner lists none of his many film and television credits. The play’s co-writer and the production’s leading man, Mr. Clooney simply notes that his last time acting in an Equity staging was in 1986; while it was at Chicago’s revered Steppenwolf Theatre, the actor points out that he “has never appeared on Broadway so … buckle up.”

Mr. Clooney might have done his fans a better service by advising them to have a strong cup of coffee. That’s because the main problem with “Good Night” — adapted by the star and a frequent collaborator, Grant Heslov, from their screenplay for the 2005 movie of the same name — and with Mr. Clooney’s performance in particular is not that they constitute a train wreck of any kind: It’s that, to the contrary, they’re kind of dull.

This is disappointing for a number of reasons. The title “Good Night, and Good Luck” refers to the signature signoff of Edward R. Murrow, the broadcasting giant, who used those words in his reports as a radio correspondent in World War II and during his subsequent career in early television news. With the 1950s series “See It Now,” Murrow tackled a number of divisive issues — none more famously than Joseph McCarthy’s reign of terror, during which scores of citizens were targeted and often prosecuted as communists.  

In the film, which Mr. Clooney also directed, he played Murrow’s producer and co-creator of that program, Fred Friendly, and cast David Strathairn, an estimable stage and screen veteran, as Murrow. With the benefit of other excellent performances — from the likes of Frank Langella, Jeff Daniels, and Robert Downey Jr. — and Robert Elswit’s period-perfect, black-and-white cinematography, the result was a taut thriller that held its grip throughout its roughly 90 minutes. 

The stage incarnation runs only about 10 minutes longer than that but is less consistent, despite the presence of an accomplished cast helmed by David Cromer, one of contemporary theater’s most eclectic and intuitive directors. Mr. Cromer, who’s also a fine actor, is especially well known for his splendid work with ensembles, in both intimate and larger settings.

With its 1,600 seats, the Winter Garden Theatre, home to “Good Night,” falls decidedly into the latter category. Scott Pask’s sprawling, stunning set makes good use of the space, allowing Mr. Cromer to follow behind-the-scenes action at the CBS Studios, where Edward — now played by Mr. Clooney — holds court, and to shift easily to other locations. 

Small screens surround the stage, alternating vintage commercials (via David Bengali’s projection design) with close-ups on Edward and his subjects. As in the film, archival footage — of McCarthy and other historical figures, from a young Roy Cohn, his notorious protégé, to Liberace — is sprinkled in. At points, a bigger screen descends to zero in on Edward, ostensibly underlining his noble use of power and presence.

Unfortunately, Mr. Clooney fails to project either of these qualities. It’s not just that he doesn’t capture Murrow’s distinctive vocal cadence and intonation the way that Mr. Strathairn did; on stage, the movie star simply can’t summon the necessary grit or, more strangely, charisma for the part. Yes, Mr. Clooney can be charming, but his Edward doesn’t command our attention the way a crusading journalist or a leading performer should.

Other portraits, too, can seem a bit muted. The silver-throated Georgia Heers is a notable exception as a jazz singer who croons standards intermittently, as the great Dianne Reeves did in the film. As Fred Friendly, Glenn Fleschler manages a witty rapport with Mr. Clooney, as does Clark Gregg in the role of Don Hollenbeck, another outspoken newscaster who suffered more for his convictions.

Here and elsewhere, Messrs. Clooney and Heslov remain essentially faithful to their screenplay, once again incorporating Murrow’s actual words in his appeals to audiences and, at one point, peers. As you might expect, there are a few seeming attempts to draw parallels to current political discord: Don remarks at one point that he feels “as if all reasonable people took a plane to Europe.” At a recent preview, many in the audience laughed knowingly or applauded.

The applause was even louder after a video montage near the end, which concludes with a clip, widely circulated in recent months, of one of our most prominent and despised public figures of the moment. Some of the clapping and hooting around me was so explosive that I wondered if people were cheering for the guy — not President Trump, by the way — though it’s more likely they were making a show of their contempt, lest anyone around them hold it in doubt.

Of course, it’s also possible that these theatergoers were enjoying a moment of genuine catharsis. In that case, given the lack of stimulation provided through much of this production, I could hardly blame them.