Nearly twenty years ago, I spoke to Edward R. Murrow’s top producer, Fred Friendly, who told me he thought of Bill Moyers as "the Murrow of our time…the broadcaster who most upholds his mantle." But while Murrow remains television journalism’s most admired historical figure, it’s all but inarguable that Moyers long ago surpassed his achievements.

This is no knock on Murrow, who, after all, spent most of his career on radio. His See It Now–the program that helped take down Joe McCarthy in 1954–enjoyed just four years of life in a regular prime-time slot before it gradually disappeared as an occasional series, unable to find a sponsor. Defenestrated at CBS, Murrow gave up on network news entirely and accepted John Kennedy’s offer to head up the USIA in 1961. But when Bill Moyers likewise found his brand of journalism unwelcome on network news, he had another option. He was able to return to PBS, where he had begun his career as a broadcaster fifteen years earlier. With his decision to found his own production company, Public Affairs Television (PAT), together with his wife and executive producer, Judith Davidson Moyers, he assured himself complete editorial independence, and in the quarter-century that followed, he fashioned a body of work without parallel in the medium’s brief history.

Who but Bill Moyers could have devoted so much time to the work of Joseph Campbell and Robert Bly; done television’s most hard-hitting reporting on the Iran/Contra scandal; investigated the media’s failure in Iraq; defined the human impact of economic inequality; examined the ability of corporations to manipulate the "public mind"; evaluated the real-world impact on local communities of corporate-driven "free trade" agreements; devoted hours and hours of TV to a poetry festival, to the Book of Genesis, to the sources of addiction and to the relationship between the environment and religion, etc.? The variety of topics, moreover, is only half the story. Moyers’s methods were unique. Where else but on a Bill Moyers program were Nobel laureates and laid-off steelworkers invited to speak at length to America, without interruption or condescension?

Bill and I have been friends–and frequent professional collaborators–for nearly two decades. But we first met in Managua in 1987, where he and his crew were talking to protesters outside the US Embassy for his landmark PBS special on The Secret Government: The Constitution in Crisis. Not long afterward, I spent months speaking to his co-workers at CBS and elsewhere for a magazine profile of him. All were eager to talk, as we were in the midst of one of many brief "Draft Moyers for President" movements, though a few were conflicted. Some felt abandoned by his decision to leave CBS and quit fighting the good fight for network news; but most remained grateful for the opportunities his work had offered them. Onetime CBS Morning News producer Jon Katz told me, "When you work with Bill, it ruins you for everyone else." Yes, Moyers would "drive the executives berserk with his agonizing over everything, and getting him on the morning news was like a three-month Kabuki dance every time. But the end result was the most brilliant stuff we ever had."

If I were forced to name a single broadcast emblematic of what Bill Moyers brought to our national conversation–and what we stand to lose with his April 30 retirement from regular broadcasting–it would be his amazing 1986 CBS documentary The Vanishing Family: Crisis in Black America. Taking on so sensitive a topic–one that had remained taboo in public discussion since the furious leftist attacks on the now infamous 1965 Moynihan Report had traumatized Pat Moynihan and nearly destroyed his career–Moyers waded into waters no one else wished to enter. Confronting a problem that had metastasized after two decades of liberal silence in the face of a relentless right-wing war on the poor, Moyers walked into the ghetto to give its residents the chance to speak for themselves.

The program was remarkable in what it did not contain. It had no "responsible" black political voices explaining away the problem of fatherless children, no white liberals offering excuses, no conservative condemnation and no experts framing the issue with sociological theory. It was just one struggling teenage single mom after another, along with more than a few absent fathers, trying to explain how they coped and why they had made the choices they had. In an age before cable, the Internet or much talk-radio, its impact was explosive, comparable, perhaps, to Murrow’s famous 1960 "Harvest of Shame" report on migrant farmworkers. (Ironically, both men did their best work at the network with one foot out the door.) Like Murrow, Moyers deployed television’s unmatched power to focus attention on the voiceless, forcing Americans to confront the humanity of those who are usually demonized or ignored. As even a conservative New York Times reviewer noted at the time, the program’s "intelligence and grace…redeems television journalism."

In choosing PBS over CBS, Moyers opted for independence over influence. This freedom has allowed him to earn a deserved reputation for being the last unapologetic liberal anywhere in broadcast television. But his most significant legacy is that, also like Murrow, he treated his audience as adult citizens of a republic, who bear collective responsibility for the society we share. The notion that television can both entertain and educate–even to the point where it challenges our most powerful ideas and institutions–was crucial to the medium’s founders. Yet it has all but disappeared in our current political culture, together with the democratic self-confidence necessary to sustain it. For the better part of forty years, Moyers and his co-workers have demonstrated, time and again, just what such self-confidence looks like. In doing so, they’ve shown the rest of us how rare and valuable this resource has become.