Forgive us, Oprah, for we have sinned

Out of America: She is the mother confessor of the United States, the woman to whom the nation's miscreants turn and tell all

The Oprah effect: Winfrey, at a campaign rally in 2007, is said to have won the election for Obama (Getty Images)

You've got the biggest PR problem in American sport since the Black Sox scandal. Worse, in fact, since baseball's Chicago White Sox only threw one baseball World Series, in 1919, while you've been stripped of no fewer than seven Tour de France cycling titles for cheating. So where do you go to rebuild your image, to seek re-invention in the land famous for second chances and second acts?

Well, you go to the woman who is said to have won the presidency for Barack Obama four years ago. You go to the woman who – even more miraculously – transported Leo Tolstoy's Anna Karenina, all 837 pages of it, back to the top of the bestseller lists more than a century after it was published. You go to she who has been described as the most powerful woman in the world. In short, you go to Oprah Winfrey.

There is, of course, no guarantee that Lance Armstrong will make a clean breast of things when he sits down with Oprah for Thursday's edition of Next Chapter, billed by her cable channel OWN, the Oprah Winfrey Network, as a series of "enlightening and in-depth conversations" with the famous.

Armstrong may have lost his titles and his reputation, comprehensively demolished in the infamous report by the US Anti-Doping Agency, arguably the most devastating official indictment of one man's sporting career ever delivered. But he has never yet admitted taking performance-enhancing drugs (PEDs): indignant denials have thus far been replaced merely by frosty silence. And there's no guarantee he'll admit it now, not least because of the small matter of possible perjury.

It's been a wretched few days for the PED brigade here, what with steroid-stained Barry Bonds and Roger Clemens, two of the greatest baseball players of any era, refused admission to the sport's venerated Hall of Fame. But remember: it wasn't drug-taking per se that saw both taken to court in recent years. It was charges of perjury and perverting the course of justice. That awareness must shape Armstrong's calculations now.

But if he is going to tell all, where better than in Oprah's national confessional? At this nadir in his affairs, it was clear Armstrong would never consent to a prosecutorial grilling on CBS's 60 Minutes, or any other of America's traditional investigative programmes. He might have done Larry King, gentler and less combative, but Larry is close to 80, and long ago lost his perch on CNN to Piers Morgan. But even King in his pomp didn't come close to Oprah.

Yes, many people could go through life without once coming across her – if you worked a regular week and weren't at home to watch her show in the afternoons during the 25 years it ran between 1986 and 2011, or if you aren't now inclined to explore the triple-digit reaches of your cable TV line-up, where OWN tends to reside.

But if you did, you were in the presence of a phenomenon. Oprah didn't invent the tabloid talk show; that distinction belongs to Phil Donohue, back in 1967. But the Oprah Winfrey Show perfected the genre. There famous people and ordinary people alike discussed their problems and acknowledged their sins. Revelations were not extracted by fierce questioning, but coaxed forth by curiosity and empathy.

"Humani nihil a me alienum puto" ("I consider nothing that is human alien to me"), wrote the Roman playwright Terence, and Oprah has always followed that maxim. Nothing humans did was off-limits for her show. On it, the abnormal was normal. She was rarely judgemental. She could be loud and earthy, sensitive, funny, tender and wise. She explored gay issues and straight issues, society's fads and society's taboos, and her own as well.

Her background helped. She was born to an unmarried teenage mother in rural Mississippi, and became pregnant herself at the age of 14 (the child, a boy, died in infancy). While still at high school, however, she landed a job in radio and never looked back. This was a truly self-made woman, who became the first black billionaire – but also an utterly human one who obsessed about her weight.

Winfrey's was the most popular talk show in US history. The lay priestess who took confessions became an oracle to her millions of devotees. Oprah's Book Club, in which every month or two she recommended a book, could add millions to the sales of the fortunate volume (and even raise Tolstoy from the dead). In 2007 and 2008, she ventured into politics for the first time, endorsing Obama. According to one study, she brought a million votes his way in the primaries, enabling him to beat Hillary Clinton and go on to win the White House. The "Oprah effect" was mighty enough to propel her for a dozen straight years on to Time magazine's list of the world's most influential people.

And now there's Armstrong, hoping in his turn to bask in the Oprah effect. And why not? If she could help secure the acceptance of gays and lesbians into the American mainstream, as many sociologists would argue, she is surely fitted now to speed the re-acceptance even of the disgraced Lance Armstrong: confession followed by expiation, and finally redemption. Maybe, but it won't be easy.

Armstrong, plainly, is not the admitting sort. The ideal Oprah subject would be Bill Clinton, empathetic like her, touchy-feely, a naughty boy with a winning smile for whom all sins are ultimately forgiven. Armstrong appears different: hard where Clinton is soft, an emblem not just of human frailty, but of human ambition and ruthlessness, too.

But one final thought. Lance may need Oprah – but right now Oprah needs Lance. OWN, by common consent too much dross and too little Winfrey, did so badly after it was launched in 2011 that Time struck her off its list last year. Ratings have improved of late, and the network may finally soon be in the black, after losing a reported $330m (£205m) in 2011. Clearly, however, as far as the Lance and Oprah show is concerned, everyone needs a blockbuster.