'Had you said a year ago that Carlos Menem would get his re-election,' said Roberto Russell, a prominent Argentine political scientist, this weekend, 'I would have laughed at you. So would everybody else. But he has done it.'

It is not the first time that Menem has had the last laugh. Argentina's president has spent much of his adult life nurturing ambitions that others found first risible, then alarming.

The latest is to alter the country's constitution to increase his chances of staying in power. On Sunday, Argentine voters went to the polls, without much enthusiasm, to elect members of a constituent assembly that is charged with re-writing a constitution ratified less than 10 years ago. It wasn't a bad constitution, in the opinion of most of the country. At least it had restored democracy after the disastrous Falklands war ended eight years of military dictatorship. But for Menem, it was the obstacle to his principal desire - a second term of office. So, like most things that get in his way, it had to go.

Despite a little local difficulty in Buenos Aires, in the form of a victory on Sunday for the Broad Front leftist coalition, it looks as if Menem will have his way - as he has in every declared ambition to date - and go down in history as the first Argentine president to serve two consecutive terms. He will also be the only president in Argentine history who will serve a total of 10 years in office. After unpicking the constitution, he only has to be re-elected. To observers of the vertiginous ascent of Carlos Menem, that looks like a formality.

The victory of Menem's Peronist party on Sunday was, like most of his triumphs, against the odds. He was born the son of Syrian immigrants in La Rioja, one of Argentina's poorest and most backward provinces, where he grew up to be a lawyer. It was a long way from the metropolitan sophistication of Buenos Aires and the wrong side of a fault line, running deep in Argentine history, between the metropolis and the provinces, between liberalism and nationalism.

Menem was a colourful figure in his youth: as an adolescent he read and re-read the history of Argentina's caudillos - the local satraps who led the fight against Buenos Aires liberalism in the mid-19th century. Standing 5ft 5in in his built-up heels, he grew his hair long and cultivated the extravagant sideburns that were the trademark of the caudillo Facundo Quiroga. For the inhabitants of the capital, Quiroga was the essence of a barbarian. For the people of the provinces, he was the spirit of heroic nationalism.

Menem reinvented that confrontation and rode to power on its back. Once in power, in the space of a day, he changed sides. 'Menem,' said Oscar Cardozo, a leading political journalist, 'is a post-modern president. He doesn't feel bound by words, especially not his own words.'

The vehicle for Menem's ascent was Peronism, Juan Domingo Peron's blend of emotional nationalism and populist anti-capitalism that gave the Argentine working class its access to political power in the Fifties.

In 1973, Peronism was triumphant in Argentina after the return from exile of the ageing Peron. Menem was elected governor of La Rioja, where the public payroll is one of the largest sources of employment. At the time, he was associated with the militant left of the party, a position he was to abandon, as he did so many others, shortly afterwards. When Peron died, the entourage of his widow, Isabelita, who assumed the presidency, was to the right and Menem followed. 'Menem,' said Oscar Cardozo, 'does not have an ideology exactly. But he has a very acute sense of power.'

When Isabelita was overthrown by a military coup in 1976, Menem was imprisoned for two years by Argentina's new military rulers. He told anyone who would listen that he would be president one day and converted in prison from his native Islamic faith to Catholicism, a necessary pre-requisite for the top job. Those who watched him were still laughing.

Out of jail, Menem set about becoming famous. He was an outsider, not only in national politics but within the Peronist movement where more conventional figures ran the party. When the military dictatorship fell, he was still an outsider. Raul Alfonsin and his Radical Party won the first election after the dictatorship on a platform of liberty and human rights and Menem had to content himself with returning to govern La Rioja. By this time he was famous - for his highly publicised marital rows and his playboy life, complete with racing cars, - but he was as far from the presidency as ever.

Alfonsin's government was to be engulfed by catastrophic economic problems. By 1987 it was clear that the next president would be Peronist. It seemed equally clear that it would be Antonio Cafiero, a veteran Peronist politician. He knew that Menem was prepared to lead a separate party if he did not win the Peronist candidacy, but Cafiero was confident. He was wrong.

Never ashamed to borrow a good idea, Menem campaigned in the provinces in what he called the Menemmobile, a copy of the Popemobile. Dressed in white, his long hair flowing, Menem appeared in communities up and down the country like a Messianic figure, promising salvation. In May 1989, he was elected president of Argentina.

Menem's campaign had been almost a religious event. He told the mesmerised crowds at his rallies: 'For the hunger of poor children, for the sadness of rich children, for the young and the old, with the flag of God, which is faith, and the flag of the people, which is the flag of the fatherland, for God, I ask you: follow me. I will not deceive you.' As he entered the presidential palace in 1989 it seemed to the metropolis that barbarism had arrived. 'I thought of emigrating,' said one prominent academic. 'It seemed like a disaster.'

Argentina was in a mess and Menem seemed likely to make it worse. Faced with hyper-inflation, he had promised massive wage rises and a tough stand on Argentina's foreign debt. He had campaigned like a Peronist - protectionist, anti-American, muscular on the Falkland Islands. If he did what he had promised, observers predicted, he would last three months. But Carlos Menem did exactly the opposite.

Five years after Menem's election, Argentina has become a model of economic liberalism: inflation is down from nearly 5,000 per cent in 1989 to a projected 4 per cent this year and the Central Bank's reserves have grown by a factor of 15. The man who once described privatisation as 'selling the fatherland' has privatised the country's elephantine public companies and pegged the currency at par with the dollar; foreign investors have flocked to Buenos Aires and the United States has no better friend in South America than Carlos Menem.

Argentina's industrialists and the voters from the rich suburbs of the capital, who previously would reach for the crucifix and garlic at the mention of Peronism, are now Menem's most ardent supporters. He has steadily dismantled the structures of social protection that Peron established, but he remains a hero to the poor. The long sideburns have gone, the hair is trimmed and coiffed by his two travelling hairdressers and the white Messianic clothes have been replaced by sharp Italian suits.

Menem has abandoned barbarism in favour of the ideology of the market. He laughs off the corruption scandals that circulate around his administration and his family, including allegations of laundering money for drugs barons. So far, few voters seem to care if the personal enrichment of his entourage is the price of prosperity.

Menem needed a two-thirds majority in congress to change the constitution and the radicals opposed him. But when he announced that he was prepared to force through a vote with two-thirds of the members present in the congress on any given day, rather than two-thirds of those elected, Raul Alfonsin, the Radical leader, was faced with a choice. He could continue to oppose Menem and risk plunging Argentina into political instability. Or he could give in and try to salvage something in the negotiations. He gave in and the radicals are now bitterly divided.

Menem, the man who believes he was placed in the presidential palace by destiny, had threatened to destroy the legitimacy of Argentine democracy and emerged as the guarantor of prosperity, continuity and stability. It only remains for his cowed and fragmented opposition to ask what is Carlos Menem's next ambition?

What will happen after 10 years in power? 'For Menem,' said a prominent political journalist, 'there is no such thing as 'after power', only 'power'.'

(Photograph omitted)