“And that’s the way it is,” Walter Cronkite famously signed off each night from “CBS Evening News.”

In these days of low public trust in mainstream news, such a declaration might seem outlandishly ambitious.

But that’s what Norah O’Donnell says she wants, as she steps on Monday into the “CBS Evening News” anchor position held for many years by Cronkite, who was often called “the most trusted man in America.”

At an appearance this week, O’Donnell, 45, was asked how she would judge success in her new role.

“The most trusted journalist in America and around the world” was how she wants to be seen, she said.

Network honchos would probably settle for something less lofty: getting the Tiffany Network, as it once was known, out of the ratings cellar for its evening news broadcasts.

CBS trails top-rated ABC and close-second NBC in that tightly edited 30 minutes that still is appointment viewing for millions of Americans.

Those who say the evening news no longer matters in the digital age are wrong.

The three news broadcasts — even now, after many years of decline — still pull in well over 20 million viewers a night, far outstripping prime-time cable-news offerings that get so much more attention.

O’Donnell won’t be the first woman to anchor a network evening broadcast. Among her predecessors: Connie Chung and Katie Couric, both at CBS. And Diane Sawyer held the ABC “World News Tonight” spot before David Muir took over in 2014.

But she does come on just as CBS is recovering from a tumultuous period over the past two years. Anchor Charlie Rose, chief executive Leslie Moonves and “60 Minutes” executive producer Jeff Fager all stepped down as the #MeToo movement roiled the company with charges of sexual misconduct and gender discrimination.

In their wake came the appointment in January of the highly respected CBS stalwart Susan Zirinsky to replace David Rhodes as the head of the news division. After more than 40 years at the network, she became the first woman to do that job.

“I would not have taken this job if Susan Zirinsky were not president,” said O’Donnell, who replaces Jeff Glor, and, before him, Scott Pelley, in the anchor chair.

Not only did Zirinsky give O’Donnell her shot, but she also will move the evening broadcast from New York to Washington this fall.

“It’s a gamble but a very smart gamble by Zirinksy,” said Tom Bettag, a former executive producer at CBS News and ABC’s “Nightline” who teaches at the University of Maryland journalism school.

He sees it as a case of CBS playing to its strengths — strong reporting from its Washington bureau including congressional correspondent Nancy Cordes and chief Washington correspondent Major Garrett — just as a hugely consequential election year approaches.

As Bettag sees it, CBS is trying to differentiate itself from the other evening newscasts by emphasizing Trump, politics and government.

And he thinks O’Donnell — “extremely smart, experienced in Washington and hard-working” — is an ideal choice, in part because of her strong, self-confident television presence.

As former “Face the Nation” moderator Bob Schieffer told me Wednesday, “she just has that something — it’s why some people are movie stars and some people aren’t.”

But beyond that, Schieffer said, O’Donnell exudes authenticity because of her credentials and experience as a Washington reporter, including a stint as White House correspondent.

She is, he said, “simply the perfect person for this.” But he added with a touch of cautious realism, “We’ll see — we have a tall hill to climb.”

O’Donnell’s debut Monday will include interviews with Amazon chief executive and Washington Post owner Jeff Bezos and with Caroline Kennedy, the author and diplomat who is the daughter of President John F. Kennedy. The idea is to mark the 50th anniversary of man’s first steps on the moon — a subject closely tied to Cronkite’s legacy.

In an interview, Zirinsky was explicit about what she’s trying to do: tie the network’s storied history to O’Donnell while looking to a more digitally oriented future in which CBS News is a 24/7 proposition.

“It’s time to shake things up,” she told me Wednesday. The move to Washington positions the broadcast for “these two years that have such import,” placing not just O’Donnell but also the whole center of gravity right where the action is.

“Washington gives us a tremendous advantage,” Zirinsky said, while noting there would be an effort to report more deeply throughout the country to counter any inside-the-Beltway insularity.

And although Zirinsky admitted that she certainly would love to move the needle on ratings, she emphasized that there’s something else at stake here: that whole trust thing.

“There is a desperate hunger for authentic, no-spin news,” Zirinsky said. “And that is the baton that’s being handed to Norah.”

Ratings aside, if O’Donnell manages to return even a smidgen of trust to the beleaguered news media, that would count as a win.

For more by Margaret Sullivan visit wapo.st/sullivan