‘The Newsroom’s’ Sam Waterston reports on his HBO character

When Sam Waterston sits down in a corner booth at a posh Beverly Hills hotel, one expects rarefied reflection from this stage and screen actor best known for his 16-season portrayal of crusading prosecutor Jack McCoy on “Law & Order” — and, sure, he gets to that. But more surprising is the way he dissolves into boyish laughter as he describes watching Jeff Daniels, his costar in HBO’s”The Newsroom,” crouched over a toilet in an explosive bathroom scene in “Dumb and Dumber.”

“I didn’t watch the movie until we already shot quite a bit [of ‘The Newsroom’],” the 71-year-old actor says in his distinguished, gravelly voice during a recent trip to Los Angeles. “You can understand how it wouldn’t be my thing. But the scene in the bathroom is absolutely genius. The expressions that take over his face — it was surprisingly impressive and outstanding.”

The way the Massachusetts native brightens when talking about his costar’s impeccable work on a toilet is similar to the pride his character takes in the news in Aaron Sorkin’s lofty ode to journalism, set inside a cable news show. Waterston plays Charlie Skinner, a kooky, bow-tie-wearing, unapologetically old-school president of the news division — or as Daniels described him in by phone, “the wizard behind the curtain ... who’s had a couple of Scotches.”

Waterston is more subdued than his TV alter ego. For the interview, he wears a suit jacket but no bow tie and keeps his voice down. Still, he finds parallels with the well-seasoned newsman he portrays: “The appetite Charlie has for news — no matter how much he’s seen and no matter how cynical that’s made him — the appetite for the news never goes away. He’s going to be that way until he’s gone. That’s kind of easy for me to relate to because that’s how I feel about acting.”

Sorkin said via email that there was no model for Charlie, “except maybe Mr. White from Superman” — the fictional character in the comics who serves as editor of the Daily Planet newspaper.

The workplace drama, which premiered last month to a solid 2.1 million viewers, attempts to make a statement about the state of cable news shows through the prism of Daniels’ Will McAvoy, a popular anchorman whose high-minded ambitions have been sullied by the chase for big ratings — that is, until his idealistic executive producer (and ex-girlfriend) MacKenzie McHale, played by Emily Mortimer, comes back into his life and urges him to reclaim the fourth estate.

“We need more idealistic people to give their lives to journalism,” Waterston said. “It could stand a little raising of the tone.”

Some critics of the show complain that Sorkin’s dialogue translates to pontification. Times television critic Mary McNamara called it a “baffling free-fall in which plot exists almost solely to support the political and cultural points Sorkin wants to make.” The New York Times suggested the show “chokes on its own sanctimony.”

Waterston energetically rejects charges that the show comes off as preachy: “I think it’s aspirational. I would only think people would use that word [preachy] in order to dismiss it because there’s a lot of opinion in it. God help us, isn’t there a lot of opinion in the talking-heads world of cable television? I think that the only thing that really drives Aaron nuts about the news business is the lying — that’s a completely bipartisan and unpreachy thing, if you ask me. It seems to me that that’s coming from some place much more visceral than where people preach from.” (Waterston then takes a swig of bourbon in honor of Charlie — the only time during the entire interview in the hotel bar.)

Although Waterston has tackled the world of journalism before (in “The Killing Fields” he played a New York Times reporter), he says it was his curiosity about cable news that piqued his interest in the part. He says he became a news junkie in the 1990s, when Bill Clinton was president. Clinton “was on a continual high-wire act,” he says. “In retrospect, I don’t know whether he was on a high-wire act or if we just got than impression because the cable news stations were selling us on the idea that everything was teetering. But it was this perfect storm and I found myself watching the news all the time.”

Waterston came to “The Newsroom” knowing he had a safe haven in Daniels, who appeared with him on stage years ago. The feeling was mutual, as Daniels noted.

“I just knew he’d be a great sounding board for me, and he was. He would check in with me over the course of the series and go, ‘How are you doing? You doing all right?’ I always enjoyed our scenes together because the two of us have a history, Charlie and Will have a history, and we were able to kind of draw on knowing each other for well over 30 years.”

Sorkin, who has admired Waterston since seeing him in a production of “Much Ado About Nothing” in the early ‘70s, believes the actor has the perfect qualities to play “Newsroom’s” wise but eccentric boss

“Sam is brilliant, funny, powerful, nuanced, and his face has a map of the world on it,” he said. “He’s also what football coaches call ‘good in the huddle’ — he’s a great leader in this ensemble cast.”

yvonne.villarreal@latimes.com