In New York, in a stadium named for Arthur Ashe, the weekend was stolen by Serena Williams, who while thanking Jehovah and her slightly offbeam father, Richard, became the first black woman to win a grand slam tennis championship since the 1950s.

In Houston meanwhile, people held their breath as Sammy Sosa dawdled on the cusp of becoming the first player to hit 60 home runs in successive seasons in America's game, baseball.

It was odd to sit in Chicago and watch Williams and Sosa hijacking the American sporting imagination. Yesterday, as the hurling final was settling into the Irish imagination, the new gridiron season began on fields across America. Black players make up 80 per cent of the cast of that particular show and are happily predominant in all American sports apart from the doggedly white, blue-collar ice hockey rinks and the preppy soccer fields.

The Irish beetling around the big cities looking for venues playing host to breakfast showings of the hurling final are yesterday's vibrant ethnic block. Sure, they swing a little weight in Washington, where white guys in suits still run the show, but the edge of life in the cities and the poverty in the cities has been ceded to others.

Early in the century the kids of the Irish and the Italians loomed large in the American sporting imagination. From Dempsey to Marciano and at most points in between the name gave away the provenance. None of this is news, but it made for a fascinating backdrop last week as Bill Bradley travelled home to Crystal City, Missouri, to add his name to the list of white folk bidding to become the next president of the United States.

Bradley isn't an electrifying personality. His speech, which formally placed him in the two-horse race for the Democratic nomination, would have rivalled in paint-drying dullness anything his near comatose rival Al Gore could come up with on a down day. Yet Bradley is maybe the most interesting character in the entire field - or will be when John McCain drops out.

Race is an issue which Bradley has always been especially passionate about. He is not a man of passions, but the race issue ignites him strangely and frees him from his grey shroud of over-intellectualism. Race and sport is a theme of his. Bradley is no Jack Lynch, but his pre-eminence on the American landscape is built partly on one of the most remarkable sports careers America has seen.

The son of a republican, middle class Missouri family (his father was a bank president), Bradley was seduced early by basketball. Six foot three inches tall at 12 years of age, he found that comfortable Crystal City didn't offer the rough and tumble playground education every great basketball player needs. So he thought his way into the game.

When Bradley played, he played in exactly the way coaches draw their diagrams. Little wonder. That's how he learned. During endless solitary practice he would, with comical earnestness, wear his father's reading glasses with cardboard taped over the bottom half of the lenses, and would attach 10 lb weights to each of his feet, then embark on endless solo dribbles around the court. The cardboard prevented him from seeing the ball and trained him to always look upward and around for a basket or a pass. The weights improved his jumping and speed.

As a kid, he walked streets performing self-devised exercises to improve his peripheral vision. He would inventory the items in shop windows while staring straight ahead down the street. By college his peripheral vision was 15 degrees better than the norm.

College. Seventy different universities clamoured for his services. He turned down the scholarship offers from all 70 and paid to attend Ivy League Princeton. There his legend truly began. By his senior year, Bradley and Cazzie Russell of Michigan, both by then Olympic gold medallists, were regarded as the greatest college basketball players in the game. They collided in a famous match in Madison Square Garden, where Russell (an alumni of Chicago playgrounds) was expected to expose Bradley as soft.

Bradley scored 41 points. Princeton only surrendered their lead when he retired injured. He guided Princeton to the NCAA finals, where they finished third. In the play-off game for third place he scored 58 points. He scored 26 points in the last nine minutes alone, draining shot after shot as the crowd chanted "I Believe, I Believe, I Believe". Unprecedented stuff for an Ivy League college.

At Princeton he was widely spoken of as a future president of the United States. After his last college game he ducked the mania and disappeared to write his final year thesis. He graduated top of the class and headed to Oxford as a Rhodes scholar, leaving the baffled New York Knicks waiting a year for his services. While at Oxford he travelled to Milan on weekends to play for a professional team. By the end of his year he was one of the greatest sports stars in Italy.

He had a wonderful career for the Knicks, where he was the only player in NBA history to have had a reputation for becoming irked when reporters would ask him about running for president. But it was with the Knicks that Bradley's racial awareness became acute.

He went on to become a three-time elected senator for New Jersey, and has spoken often about travelling in the 1960s with black team-mates who were unable to eat in the same places as him. In the early days of player product endorsement deals the suits would loiter at the lockers of the white players only.

As Bradley begins a well-funded nomination campaign, running to the left of Al Gore, his passion on the issue of race will be a building block. Bradley embarrassed himself in the 1980s with an unexplained flipflop on the Nicaragua Sandinistas, but redeemed his credentials with a brutally frank race speech at the 1992 Democratic convention in the wake of the LA riots. Last week, as the great sports star of the 1960s made the move which people have been urging him to make since 1988, he can't have helped but notice that the minstrels beguiling today's American sports fans are almost all of one colour. Unlike the Irish and the Italians, whose names dominated team sheets for the first half of this century, however, there has been precious little movement of black people into the corridors of power.

With polls showing him neck and neck with Gore in New Hampshire it is possible that Bradley can build a base on his sincerity on the race issue. But whether he and people like him can build a ladder which enables Serena William's kids and Sammy Sosa's kids to advance in fields other than sports and entertainment will be the true challenge of the next century.

It's 50 years since Jackie Robinson became the first black baseball star. Who knew then that sport would be the ceiling, not the floor?