Former French prime minister François Fillon confirmed his excellent score in the first round of the right's primary elections and crushed another former French prime minister, Alain Juppé, in the second round, to win the presidential nomination last week. I admit to having been unable to foresee the results of the French elections. I was quite sure the former French president Nicolas Sarkozy would be unable to win the elections for various reasons. I like Fillon's personality and consider him to be the most qualified of the right-wing candidates. He was a very solid and popular prime minister. But I was sceptical regarding his programme, as nobody has ever won a French election with an ultra-liberal economic programme. If you add Fillon's very conservative views on cultural issues, he did not look like the ideal candidate. Nevertheless, he won and proved the pundits wrong. But the experts have many explanations for this: Juppé mishandled his electoral campaign, they claim, though this is easy to say with the benefit of hindsight. He thought he had to see off Sarkozy's candidacy and knew that the former president was good at cajoling the most right-wing components of the electorate. So he decided to present himself as a centrist. This was not merely a tactical choice, as he also tried to be himself and to advocate the values he believes in. It turned out that this was the wrong approach to the election. The French right wanted a right-wing candidate, not a centrist one. And it has been exasperated by French President François Hollande's political options, including his cautiousness on economic and social issues and his ultra-liberalism on cultural ones. At best, Juppé's programme was tailored to a presidential election and not to the right's primary. I personally thought his economic choices were sounder than Fillon's, but he was wrong on cultural issues. He strongly underestimated the anger of the electorate on French identity, against fundamentalist Islam, on multiculturalism, and on the European Union. Some friends of mine also told me that many in France were fed up with the state and with statism and wanted to try economic liberalism instead. I doubt this is true, but I no longer live in France and I do not trust opinion surveys. What looks certain is the social profile of the voters who participated in the primary. They belong to the middle classes. The poor were absent, and pollsters tend to think the latter will vote for the extremes of either the extreme right or the extreme left in the actual elections. Sarkozy was able in the 2007 presidential elections to broaden his social base and to make inroads into this segment of the population. The question is whether Fillon will now be able to broaden his base either towards the centre or the extreme right. He said he wanted to eliminate the latter, not in the second round of the presidential elections, but in the first. It is too early to tell if this is a realistic prospect. But his victory speech exalted “the nation,” “French values” and the “people.” These things are supposed to appeal to the right. The leaders of the extreme-right Front National Party then went on the counter-attack and said that Fillon when prime minister had participated in the inauguration of a mosque. This may help Fillon if he opts to say that he targets Islamist fundamentalism and not Islam. But selling Fillon's programme to the poor will be difficult. His main argument will probably be “nothing else worked, so let's try this.” The centre is a different story. There are many centre-right political parties in France, and most of them supported the candidacy of Juppé. Most of their members are now trying to switch their allegiances and to support Fillon. It is clear that this will be easy for some. Others, however, are uneasy with Fillon's tough programme. Pundits say Fillon's kind of right leaves a lot of space for a centrist programme to emerge. But there are still many problems: The centrists are very different people and include Christian democrats, liberals, rightist radical party members, leftist radical party members and so on. Moreover, there is a centre right and a centre left in France. No candidate can fully satisfy the whole centrist spectrum, even if the rejection of the others' programmes could be an incentive. In fact, there is already a centre-left candidate in former finance minister Emmanuel Macron. A centre-right one, François Bayrou, is also pondering his options. There is not enough space for both. Related to what happens in the centre is speculation about whether Fillon will modify his programme, and if so when. A political adage says that you talk to voters during the first round of the presidential election in France and then you recalibrate your message if you reach the second round. Fillon has ruled out this possibility, as his consistency and his temperament plead for no change, but we must not rule it out. A lot will depend on the other candidates. More accurately, a lot will depend on how the centre and the left proceed, and vice versa. The left's behaviour has been extraordinary. Up until now, I thought that the left's leading figures, with the exception of Hollande and Socialist Party General-Secretary Jean-Claude Cambadelis, believed the 2017 elections were lost and that they were preparing for the next ones. But Fillon's candidacy opens a window of opportunity for them. The economic situation of the country is improving, and this means the legacy of the presidency looks better. However, there are many lefts in France, and they are divided by deep differences. Many candidates say they are not going to participate in the left's primary elections, but will instead run directly for the presidency. Moreover, Hollande is severely contested even in his own Party, and his own Prime Minister Manuel Valls, is considering running for the presidency. The public opinion surveys consistently deliver the same message: That the candidates who are directly running for the presidency, both centre-left Macron and extreme-left Mélenchon, are scoring better than the official Socialist Party candidate. But this could change. First of all, opinion is volatile. Second, things will be clearer when Hollande announces his decision on whether or not he intends to run. If he says he will run for another mandate, the party's base will pressure its leaders for unity. Hollande thinks that the uncertainty is the cause of the destructive divisions currently afflicting the party, and he also thinks that the right's primary results proved one thing: That the French want a well- known figure as president and that times of crisis are not times of experimentation. But this assumes that what is valid for the right is also valid for the left. I believe this is true, but we might nevertheless be surprised. The writer is a professor of international relations at the Collège de France and a visiting professor at Cairo University.