It was all so different just two years ago. When Eminem toured this country in February 2001, he was reviled and revered like few pop stars since The Sex Pistols. He was being sued by everyone from his own mother to a bouncer whom he had allegedly pistol-whipped; his wife, Kim, had just taken an overdose in despair at his treatment of her; and his lyrics - claiming to have killed O J Simpson's wife and armed the Columbine killers, and to want to kill his mother, his father and his wife - had outraged everyone from Ann Widdecombe to gay and feminist campaigners, who picketed his shows. At that peak of notoriety, his multi-layered No 1 single of fan obsession, "Stan", was still fresh in everyone's minds, confirming a talent near genius. That winter, everyone I knew wanted, even needed, to talk about Eminem.
The only problem was the tour itself. The Eminem I saw then was no folk devil, and no genius either. Though he had brought expensive sets, and though he wielded an (unplugged) chainsaw, nothing could hide what a shy, slight, uncharismatic performer he was. He was kindly attentive to his mostly pre-teen, female fans, and accusations of evil evaporated on his appearance in the mundane flesh. He has never been taken quite as seriously since.
For his return tomorrow in Milton Keynes, the show at least should be better. Whereas, in 2001, he brought a replica of his old Detroit shack, in recent months he has been touring America with a carnivalesque spectacular, with himself as ringmaster over a lurid sequence of American sins. The backdrop is a Ferris wheel and fairground ride mouth, with police sirens and glitter showers, too. Most daring is a Columbine-recalling cartoon, in which his abused fans shoot their schoolmates, while he coolly wipes blood from his face, to reveal dollar signs.
The support is from Cypress Hill, Xzibit and his protégé 50 Cent - the bullet-riddled new star rapper, whose appearance is now more keenly awaited than his mentor's - so fans should get their money's worth. But the problem of Eminem's diminished notoriety remains. As he raps on "Business", his forthcoming single: "You ain't even impressed no more. You're used to it."
It is not just a question of those disappointing gigs. The changes in Eminem since he was last here have been profound. He has released two massive-selling albums, The Eminem Show and the 8 Mile soundtrack, and his biggest single, "Lose Yourself", and, most important, he has starred in 8 Mile, the semi-autobiographical film, which has levered open the world's mainstream. But at the same time, the sources of his raging art in his early life, the very dramas 8 Mile describes, have been gently fading. All the court cases that threatened him in 2001 have been settled. The mother he famously hates has been cut out of his life, and he and his now ex-wife, Kim, have been reconciled. Court orders have stopped him drinking and drugging, leaving rap's so-called "bad boy" clean and healthy. As he promised on a single last year, he has cleaned out his closet.
Eminem now spends his days raising his six-year-old daughter, Hailie, in his gated mansion outside Detroit, or dutifully working in the studio. His psychotic alter ego, Slim Shady, has quietly been killed. And, in this period of calm, even enervation, laziness is detectable, in an artist who until recently insisted on the highest standards. His guest-raps on albums by Xzibit and 50 Cent have been absent-minded; the video for his last single, "Say Goodbye to Hollywood", was random concert footage. Acutely aware of rap stars' short shelf-lives, Eminem, now 30, has talked increasingly of stepping back into a producer's role. But if you think Marshall Mathers is really finished, you are premature. In achievement and potential, he still dwarfs his rivals.
8 Mile is the most obvious landmark. Though it is more conservative and compromised than any of his albums, Eminem's iron will in learning how to act well enough to carry the film (when, as its director, Curtis Hanson, told me, he found the task "unnatural") has put Hollywood at his feet, like no pop star since Presley. And, deeply conscious of the King's film decline, Eminem is less likely to squander his chance. As important is the musical breakthrough that Hanson forced from him when he made him write "Lose Yourself" in the voice of his movie character, Rabbit. "It was a struggle for him," Hanson told me. "His music up to that point was extremely personal and self-referential." The song's success means that, even without drama in his life, Eminem can continue.
The Eminem Show, too, has opened up new, radical avenues. Underestimated on its release because of lacklustre singles, it is the most politically confrontational record released since September 11. As dissent was wiped from his country's TV screens, and his President's approval-ratings were monumental, he set out, on "Square Dance", a modern "Desolation Row" of teens snatched for military service, as terrorists wrecked trains and chaos ruled. He named Bush as his personal enemy and told listeners not to join the US Army. "When I say 'Hussein', you say 'Shady'," he murmured, a different kind of public enemy now. He had no natural dissenting community behind him, as Dylan did in the Sixties. But, writing almost as a father to his fans, the new, responsible Slim could not help speaking out. His provocations, for the first time, were about life and death.
You may not see that in Milton Keynes. If he had attended the Oscars this year, Eminem would have offered no Michael Moore moment. Loyal to his corporate label masters for the chance they gave him after early years of struggle, his public speeches are as timidly vapid as his stage presence, dully dissing other rappers, not Dubya. But as an American artist, on record and film, he is becoming fearless. With his past's closet finally stripped and shut, what Eminem raps about next will be his greatest test.
Eminem's UK tour starts at the Milton Keynes Bowl (0870 120 2228) tomorrow. Nick Hasted's book 'The Dark Story of Eminem' (Omnibus, £12.95) is out nowReuse content