Only 60 years ago they had separate baseball leagues for blacks and whites. Now, if you have been able to tear yourself away from such questions as “whither Arsenal?” and “who Pussycat Dolls?”, you will have noticed that the United States of America has a black President-elect.

Barack Obama owes it all to Tiger Woods. Well, some of it. He also has a debt to great American athletes across the 20th century. Sport not only reflects society, it is a significant force in changing it. The road that led to the election of Obama has black athletes as its milestones, but sport was also one of the bulldozers that shaped it.

In the beginning was Jesse Owens. He was the black American who went to the Berlin Olympic Games of 1936 and blasted the myth of Aryan racial supremacy. He won four gold medals and Hitler famously did not shake his hand. But when he returned to divided America, Franklin D. Roosevelt didn’t shake his hand either, nor did he get to sit at the front of the bus. For all that, Owens stood for an excellence you cannot argue about. As such, he helped to change America.

Then came Joe Louis. In 1938 Louis boxed the German champion, Max Schmeling, in New York. In the tensions of those fraught times, a black man – the Brown Bomber – found himself in the unexpected position of fighting a symbolic battle for the pride of America. Louis said later: “The whole damned country was depending on me.” A comic joked that Louis was the only black man to be a great white hope. Louis took Schmeling apart in 2min 4sec and America had a black hero. Louis later joined the segregated Army.

After the war, in 1947, Jackie Robinson became the first black man to play Major League Baseball since 1889, when the sport was segregated. He joined the Brooklyn Dodgers in the face of ferocious opposition from the sport, the spectators and his own side. The Dodgers manager told his team: “He will make us all rich,” an argument that always gets listened to in the US, or anywhere else for that matter.

But it was the abuse that Robinson got from the Philadelphia Phillies that united the team around him. Robinson showed himself to be a good enough player and a strong enough man to rise above the issue of race. He hit more than 100 home runs in six seasons and batted .311. These numbers are unanswerable. That is the source of sport’s power.

The 1950s brought Althea Gibson. She was the daughter of sharecroppers and came from Harlem, but she could play tennis all right. And that is rather the point I am making here; or, if you prefer, it is the point sport has been making over the past century.

Because it doesn’t matter if you are a millionaire Wasp (White Anglo-Saxon Protestant) or the Queen of England; you still won’t win a tennis match against a better tennis player. Sport is perhaps the closest thing we have as a public and objective measure of worth. There was no on-the-other-hand and look-at-it-this-way when Louis smashed Schmeling or when Gibson walloped her way to victory in five grand-slam tournaments. Sometimes blacks are better than whites; and no one can duck that truth.

That’s why sport is not just a passive thing that reflects the changes that go on around it. It also actively drives the changes in society.

So far as the race issue is concerned, sport has changed the way we think, changed the way we live. In the US, which has the most highly developed sports industry the world has seen, this truth counts double.

Tommie Smith and John Carlos won gold and bronze in the 200 metres at the 1968 Olympic Games in Mexico City and at the medal ceremony they staged their beautifully eloquent protest. Their Black Power salutes were an unforgettable statement of America’s divisions. Carlos and Smith were seen by many Americans as traitors; as truth-telling heroes by others. They became national treasures in retrospect, in the post1960s rewriting of history. There is now a statue commemorating that high-fisted ceremony at San Jose, Smith’s old university.

Now we come to the most complex figure of all. The story of Muhammad Ali is one of revisionism. Those of us who were there in the Sixties recall a time not of freedom but of bitter oppositions. It was Us against Them, and Ali was a polarising figure.

His brilliance made him unavoidable. His claim that a black man could be pretty was acutely disturbing. His change of name – rejecting his “slave name” – meant that you confronted big issues every time his name was spoken. And he did a lot of speaking himself, mostly about separate nations for blacks and whites. Ali didn’t want civil rights, he wanted the partition of America.

He was a divisive figure who became a unifying one. As the tide turned on Vietnam and the shocking ideas of the Sixties became the commonplace of the Seventies, Ali was transfigured into a national hero. As an athlete of genius, he became nothing less than a symbol of all that makes America great. The patriots who hated him now loved him, for he was an emblem of the self-congratulation that America deserved as the processes that led to a more integrated society became irreversible.

Black heroes were first pioneers and then radicals. The next step was to become smug and bourgeois. No one exemplified this better than Michael Jordan. Basketball, a ghetto game, became a nationwide passion, the richest and glitziest sport in the calendar.

Jordan was at the heart of this, a dazzlingly brilliant player in a team sport that tends to showcase its stars. Jordan was one of the most compulsively viewable athletes that ever lived and became sport’s first corporate package. He sought greatness, not by changing the world, but by selling plimsolls. Perhaps the only memorable thing he has ever said is: “Republicans buy sneakers too.”

Tiger Woods took this to its logical extreme. He is so deeply involved in corporate blandness that he has become incomprehensible. His father said that he would change the course of humanity. Instead, Woods, as the ultimate expression of America, became the face of American Express.

Golf was the white man’s sport: the sport of the rich, the sport of the boss. Now white golfers have a black role model – a black man to envy, for his game, for his wealth, for his quiet elegance, for his trophy family, for his ultimate plausibility. With Woods, race ceases to be an issue. Woods, like his President-elect, seems neither black nor white. The question of colour is no longer asked, for it has found its ultimate answer.

Now Britain has a Tiger Woods figure of its own. Lewis Carl Davidson Hamilton (named after Carl Lewis, the American athlete) is a man no one patronises and everyone envies, a man of all colours or of none, a man whom all admire and none can reach. How long before we have a black prime minister? Answer: a lot sooner than it seemed last week.