“There'll never be another Walter Cronkite.” 

We'll no doubt hear that said again and again over the next few days. And of course there won't, he was unique. But there can't be another Walter Cronkite either, because his circumstances were unique.

With all of his ability and talent, Cronkite the man could not become Cronkite the phenomenon, “the most trusted man in America.” The world of television in which that was possible no longer exists.

Walter Cronkite was what is now disparaged as a “voice of God anchor.” That is unfair. Cronkite was the direct descendant in television of Edward R. Murrow in radio. He began in radio as one of the “Murrow boys” covering World War II in Europe.

With that heritage came the style of Murrow, reporting the German blitz, standing on the BBC's roof and beginning with the famous “This...is London.” The Murrow style left its mark on CBS news in a certain dramatic insistence, elegance of writing and touch of formality. That style is out of fashion but it gave viewers a sense of gravitas, of knowledge and trustworthiness.

I was never a regular Cronkite viewer. My Dad preferred Chet Huntley and David Brinkley when I was growing up and I stuck with NBC and their successors, John Chancellor and Tom Brokaw. I must have absorbed the style because, eventually, in the 1980s, I became an NBC correspondent. We were essentially a bit more relaxed and informal, I thought.

More important than the style was situation. There were only three networks and only three evening newscasts-or, some said, two-and-a-half. CBS and NBC were at the top and ABC, for much of his time in the anchor chair, a distant third.

The three-network evening news programs were what is called “appointment viewing.” In NBC correspondent Linda Ellerbee's description, you sat down for half an hour while the best people in the business told you what happened that day.

A now-amazing amount of effort went in to creating those half hours. It was all about the art or craft of the self-contained story, the “package” in industry jargon. You were creating one-and-a-half to two minute mini-movies. Open with your best shot and tell a story with a beginning, a middle, and an end. End with your second-best shot or your “stand-up,” talking to the camera. All the while write to the video -- keep your words locked to the pictures, talking shot by shot about what's happening. To keep the viewer satisfied and interested for half an hour, that was the only way. The goal was a certain sheen of quality.

It's not clear exactly when the changeover happened, but some time in the early 1990s, the nightly news was no longer a regular appointment for the millions it once had been. Before, there was there was no cable news and no internet that had already told people what they wanted to know during the day. After, the audience fragmented dramatically.

No, I'm not talking about when I had to walk five miles to school in the snow. It isn't all better or all worse now, it's just different. No one man or woman, however talented, could now occupy the central place in American news that Walter Cronkite did.

Think about that. Three anchors, a common experience shared by most Americans, and one man they came to trust the most. 

That's the way it was.