Barely had Mohammed Merah leapt from his bathroom widow in Toulouse yesterday, still blasting away with his gun, than politicians and experts were analysing just what it might mean for the President and the other candidates in the coming election.

It's unseemly. It's obscene. It has precious little to do with the facts of the case, the question of religion or the future of society in France. But it is what politics is now about, as much in France as the US.

And, of course, it does matter in electoral terms. Think back only two days when the gunman was thought to be a man of the extreme right, very probably a dismissed soldier, who was as eager to take his revenge on Muslims and blacks as Jews. Then it seemed as if the loser might be Marine Le Pen, the leader of the National Front, and the question was whether Sarkozy could draw some of her support to him or whether the Socialists, under Francois Hollande, would reap the benefit.

Once the assassin was fingered as a Muslim with allegedly al-Qa'ida connections, however, the whole focus changed. Now it is Le Pen, despite the halt to campaigning during this time, who is on the offensive again with a rallying call to "fight this war against these politico-religious fundamentalists who are killing our Christian children, our young Christian men", and Sarkozy, already tacking hard to the right, who is caught trying to catch up.

On the one hand, he needs to be statesmanlike and, as President, above it all; on the other hand, he wants to garner the emotions and the votes of those who want to use this as a good reason for reducing immigration and putting Muslims within France in their place.

There doesn't seem much doubt which way Sarkozy, ever hyperactive, will turn. Even without an election, he has long been fierce in his opposition to immigration and his rejection of multiculturalism. As Interior Minister during the riots of 2005, he dismissed protesters as rabble. As President, he has urged new laws restricting the veil and halal meat.

For all the public statements over the past few days on the need for national unity, France remains a deeply racist country. The threat of Muslim terror has allowed the French to transfer their resentments away from the Jewish population to the Arab one, and to feel the better for it. But the sentiments are exactly the same and made only the worse by rising unemployment and slowing growth.

Mohammed Merah's trail of death will only serve to make such prejudices more publicly acceptable. Even the liberal left in France will find it hard to make him into a martyr for racism. They shouldn't be too thrown. Mohammed Merah's name may be no help, but his case is peculiar. It's not the kind of grand attack on society in the manner of the July bombings in London and which al-Qa'ida would normally seek to arouse.

Instead, there remains something very personal about these killings which would belie generalisations. Had the killer survived, the right could have continued to play on the statements and information which would have come out over the coming weeks of campaigning.

As it is, Merah wasn't taken alive, as the police had planned, but died in a peculiarly cinematic and unsatisfactory (for the authorities) way. The questions which will now surface will be as much about police incompetence as his support.

How, given that he was on the radar of the intelligence and security forces, was he not stopped sooner? Why were the police unable to capture him in the end? Why was the knowledge of his time in Afghanistan not joined up with suspicions about him at home? It is right that these questions are asked.

There is far too much talk about grander themes of race relations, ethnic differences and religious motivations, and far too little acceptance of the simple fact that these cases are uncommon, they have always occurred through history and society's best defence remains good policing, not draconian legislation.

Mohammed Merah should have been caught even before his first murder. Whether you blame the failure to do so on Sarkozy as head of government, the police or Muslim extremists will no doubt be the stuff of the election in the coming weeks.

It probably won't make that much difference. It will be economics, as always, not race which will probably determine the outcome. The nearest parallel to events in Toulouse is not the July 7 bombings here in the UK, but Norway.

Anders Behring Breivik, who killed over 90 people in a murderous spree last summer, is a right-wing fanatic from the opposite end of the spectrum to Merah. Yet Norwegian politicians and the media made little of this in the aftermath or even during his arraignment. Instead, they worked to bring the nation together in a solemn moment of mourning.

Sarkozy has the opportunity to do the same in France if he wanted to step back and up to be the voice of the French people in the way that President Clinton managed after the Oklahoma City killings in the US. One can't see him doing it. The temptations of electioneering are just too great.