The trail of death began with a stolen scooter and the murder of a French soldier of North African origin near Toulouse, in the south of France.

Ten days later a man on a scooter shot three more soldiers, paratroopers, two of them of North African origin, the third a black man from the French Caribbean. Two of the men died; one is in a coma.

Four days after that, a scooter pulled up outside a Jewish school in Toulouse. Within seconds, three children and a teacher were dead. The teacher was a rabbi and two of the children were his. The gunman disappeared.

This was serial murder, racial murder, and it stunned the country and its leaders who just happened to be in the midst of an already bitter and racially divisive presidential election campaign.

Police conducted a massive manhunt, then cornered and exchanged gunfire with the man they say admitted to being the killer at his apartment not far from the school. After a 32-hour standoff, the man, identified as 24-year-old Mohamed Merah, was dead.

He was, the authorities said, a Frenchman of Algerian origin, a man with self-proclaimed links to al-Qaeda.

He and his brother, who was arrested, told police the two wanted to avenge the deaths of Palestinian children, attack the French army for its interventions abroad and "bring the French Republic to its knees."

Change in tone

Until the murders at the Jewish school earlier this week, France's leaders had been engaged in an increasingly nasty campaign to elect a new president. Blood now spattered the campaign and it was abruptly paused.

A campaigning President Nicolas Sarkozy at the ceremony on March 21, 2012, paying tribute to one of three soldiers killed by a gunman in southern France.

The incumbent, Nicolas Sarkozy, running from behind and trying to win a second term, immediately flew to Toulouse. His Socialist opponent, François Hollande, arrived a few hours later.

This would no longer be a week of rallies and speeches and partisan bickering but of mourning and funerals.

To understand French politics, it is helpful to look at the French president as an elected monarch whose role, in a time of national trauma, is to stand and speak for the country.

But assuaging grief and offering comfort do not come naturally to Sarkozy. Bellicosity is his default position.

"When you grab a little girl to put a bullet in her head, without leaving her any chance, you are a monster. An anti-Semitic monster, but first of all a monster," was his instinctive way of dealing with the events of the week.

Muscular words but almost no one questioned the tone.

In an instant, Sarkozy transformed himself into the country's mourner-in-chief, standing grimly at the school, standing grimly at the airport at the ceremony of farewell for the four Jewish victims whose bodies were flown to Israel for burial, standing grimly at the military funeral for the dead soldiers.

He dominated the week, reducing his rivals to extras in the march of ceremonials.

Pointing the finger

Only one rival, François Bayrou, leader of the centrist Democratic Movement and challenging for third place in the polls, drew a line back from the murders to the vocabulary of the presidential campaign to date.

"Pointing the finger at some people because of their presence in the country, or their origin, or their social situation, can enflame passions and emotion," Bayrou said, a clear allusion to Sarkozy and the themes the president had been campaigning on.

Operating on the principle that he would not be outflanked on the right, Sarkozy had spent the previous weeks, along with his ministers, fishing for voters from the far-right Front National whose leader, Marine le Pen, stood at 15 per cent in the polls (just slightly ahead of Bayrou).

Sarkozy's most notable contribution was to announce that France had "too many foreigners" and that he would reduce the numbers of those coming from outside the European Union from about 200,000 to 100,000 a year.

At the same time, his minister of the interior said that not all civilizations were of the same value and that, in some cases, "the French don't feel at home where they live."

Then the prime minister, François Fillon, suggested that both Jews and Muslims might want to rethink their preparation of halal and kosher meat. These were "ancestral traditions" that didn't mean much anymore, he said.

Worked before

There was method in these divisive hints. They signaled to Front National voters that Sarkozy and co. were their natural allies. It had worked before in the 2007 presidential election. In the second runoff round against the socialist Ségolène Royal, Sarkozy swept up most of the Front National votes and won a convincing victory.

It seemed to be achieving success this time around as well. A month ago, only about a third of Front National voters said they would vote for Sarkozy in the second round. Now the number is reported to be around 44 per cent.

Fishing on the right is especially important in the south of France. It was to this region that tens of thousands of "pieds noirs," French settlers, many of them Jews, moved after Algeria broke from France following a long and bloody war of independence 50 years ago.

This area has long been a Front National stronghold. In the 1990s, the party controlled four municipalities in the south and would often have support in the 30 to 40 per cent range.

What's more, National Front's power flowed from the tension created by the presence of growing Muslim minorities, people from North Africa who came in search of work and often occupied entire districts.

Then came the murders — the racial, religiously-tinged murders of the past two weeks, and the candidate of division became the president of unity, dictating the new terms of the campaign, or rather non-campaign.

He, Sarkozy, would direct the manhunt and stand above the fray; Hollande, his main opponent, would have to stand silent, fuming, worried that a wrong word might undermine his lead in a race that once had appeared so comfortable.

Sarkozy, the leader who preached and promised law and order, presided over a dramatic return to order. The monster, a terrorist monster no less, had been contained. The republic had shown its strength.

Napoleon, a short, frenetic leader to whom Sarkozy has often been compared, once said he wanted his generals to be lucky. At a key, possibly defining moment in this current political battle, Sarkozy might just be savouring that same twist of fate.