Supreme Court Justice Hugo Black famously wrote that the purpose of a free-and-unfettered press is “to serve the governed not the governors.” Somebody should try telling that to Donald Trump, who believes the Fourth Estate’s purpose is to merely sing his praises. Sadly, a lot of people turning into a certain pro-Trump cable news network agree. And they’re the target audience of “The Post,” Steven Spielberg’s pulse-quickening account of how another megalomaniac president tried, as one newsman put it, poop all over the First Amendment.


That would be Richard Nixon, who sicced all the president’s men on any newspaper daring to publish a government-damning tome titled “U.S.-Vietnam Relations, 1945-1967.” or, as it’s become better known, “The Pentagon Papers.” They were stolen from the Defense Department by a Pentagon contractor named Daniel Ellsberg, who as the Edward Snowden of his day, sought to let the government’s bosses, aka the American people, know what kind of funny business their elected officials were up to when no one was looking.


One wonders if Spielberg is having a giggle by casting TV’s consummate Russian spy, Matthew Rhys of “The Americans,” as Ellsberg in a handful of scenes where the hero/traitor passes thousands of pages of the Robert McNamara-ordered study he helped compile onto the nation’s two newspapers of record, The New York Times and The Washington Post. Oddly, it was the former that did most of the heavy lifting under the guidance of executive editor Abe Rosenthal (Michael Stuhlbarg). But for some reason the film makes The Times the heavy, a preening peacock eager to rattle the cage of its little brother down in D.C. But then Spielberg has always been about championing the underdog, which The Post was back in 1971 under the stewardship of its esteemed owner, Katharine Graham.


She was the proverbial woman in a man’s world, the lone lady among the big-boy dailies. To make her fight even more uphill, the movie reminds us that she never intended to be in the newspaper business. Then, out of the blue, her husband, Phil, killed himself and control of the rag fell into her hands whether she wanted to run The Post or not. That reluctant-hero angle is an aspect Spielberg and his writers Liz Hannah and Josh Singer milk for all it’s worth in telling how The Post picked up the fight after The Times was enjoined from publishing any more of the documents. And you’re glad they do, especially with Meryl Streep filling Graham’s sensible shoes. In a word, she’s magnificent, and when it comes time to compile her legacy, this performance, one full of fear, confidence, verve and doubt, will rank among her best.


She subtly slathers layer upon layer of subtext to a character so deep I don’t think any other actor could play her. But Streep consistently finds a way, clearly relishing the chance to portray a pioneer in the struggle to break the glass ceiling; and watching her do it by butting heads with no less than POTUS is exhilarating. Graham had help, of course, from famed Post executive editor Ben Bradlee, still a year away from spearheading journalism’s finest hour when he headed the paper’s renowned Watergate investigation.


Bradlee, a Boston native with a thick voice that roared with authority, was so perfectly played by Jason Robards in his Oscar-winning turn in “All the President’s Men” that no one who follows will ever stand a chance. And such is the case for a hopelessly miscast Tom Hanks. That “nice guy” quality that served him so well in so many roles is an absolute killer here, as he proves incapable of being gruff and demanding. He also relies far too much on all those overly familiar Hanksisms that instantly take you out of the movie. He supposed to be the yang to Streep’s yin, but it never happens.


The result is a yen for more yin from Streep, who never fails to be the most interesting actor in the room. But the writers steadfastly refuse to see it, opting to go for the obvious “will they or won’t they publish” pap over the more fascinating character study of a woman trying to hold it together at a time when she’s dealing not just with her husband’s sudden death, but also a pending plan to take The Post public and, of course, the very realistic chance she could go to prison for printing any part of the Pentagon Papers.


You expect more from Singer, who shared an Oscar with Tom McCarthy for penning 2016 Best Picture-winner, “Spotlight.” Here he mostly coasts, giving into Spielberg’s taint for cuteness, like a running gag about Bradlee’s young daughter, Marina, making bundles of cash off the lawyers and reporters filling the family’s Georgetown residence to pour over thousands of pages of stolen government documents. And what’s up with opening the movie with a sequence in Vietnam, circa 1966, accompanied by the Creedence Clearwater Revival classic, “Green River,” a song that wasn’t even recorded until 1969?


An even greater liability for “The Post” is its structure. Unlike the vastly superior “Spotlight” and “All the President’s Men,” this journalism tale isn’t a procedural full of reporters gathering clues and assembling the pieces in a undeterred quest for truth. It’s more of a boardroom-based legal quagmire involving lawyers, elitist editors and smug investors; not a down-on-the-street fight waged by craggy, veteran reporters who favor whiskey over bourbon.


Still, thanks to Streep, “The Post” is far from yesterday’s news. In fact, its 47-year-old story couldn’t be more relevant, as our current government wages an all-out war on the champion of the people by callously labeling what we do as “fake news.” As the movie proves, journalists might get things wrong, but you can always count on it being corrected the next day. Nothing signifies that quest for the truth more than the last line Streep utters as Graham, telling Bradlee — as the presses start to roll — that her late husband used to say “newspapers are the first rough draft of history.” Then she adds, “That’s good, isn’t it?” It is, and I’m sure you’ll agree after sitting down with what turns out to be — mistakes and all — a pretty darn good read about journalists, politicians and how their once cozy relationship has irreparably gone south.


“The Post”


Cast includes Meryl Streep, Tom Hanks, Michael Stuhlbarg, Bob Odenkirk and Tracy Letts.


(PG-13 for language and brief war violence.)


Grade: B