With the lone killer shooting dead three children and an adult at a Jewish school in Toulouse on Monday morning, and a link being established with the murder of soldiers of Arab and French-Caribbean origin, everyone in France understands that the political stakes are high.
This is not a Columbine-style shooting, but a cold-blooded, well-planned targeting of minority groups: Arab, Jewish, black. But with no claim of responsibility or any clear indication of who is behind it.
The election campaign has apparently been suspended, but in reality it has merely continued in disguise – with one preoccupation in every candidate's mind: how not to make mistakes that might weigh heavily on polling day.
Three of the four leading candidates in opinion polls – President Nicolas Sarkozy, his Socialist challenger François Hollande and the centrist candidate François Bayrou – rushed to Toulouse on Monday, to express (and be seen expressing) compassion and solidarity with the mourning Jewish community. Only one remained behind: Marine Le Pen, candidate of the far-right National Front.
Le Pen's silence – she also cancelled a TV appearance on Monday night – reveals an unspoken fear: what if the killer were connected to the National Front? In recent times she has been attempting to move the party towards respectability, although under the leadership of her father, Jean-Marie, a former paratrooper accused of torture in Algeria, the party didn't mind associating with less presentable individuals.
And for as long as the killer has not been caught, and his motivation remains unclear, this question will hang over French political debate and Le Pen will be kept wondering how much damage this murderous assault on minority groups will do to her already troubled campaign.
Yet the same is true for President Sarkozy, who has recently been accused of flirting with the ideas of the National Front in an attempt to woo voters who succumbed to Le Pen's populist appeal – leading to the Wall Street Journal calling him "Nicolas Le Pen", in an editorial.
Bayrou pointed to this climate of hatred towards immigrants and their descendants as a possible backdrop to the killings on the first day of the tragedy. And while he didn't go as far as accusing the president of stoking this, he was as blunt and clear as circumstances allowed. Yet his accusations could backfire if the initial hints of neo-nazi, racist and antisemitic motivations are proved wrong.
But if the killer did indeed have a xenophobic motivation then Sarkozy could well be embarrassed by past statements, including one by his interior minister and close ally Claude Guéant, who said that not all civilisations were of equal value. And he will not escape the accusation of having created the climate that fostered such attacks.
But for the moment, Sarkozy is at his best: ordering security forces into action, organising ceremonies for the victims, and making martial pronouncements. It reminds the French people of how he helped solve a hostage crisis in a school in his hometown of Neuilly, west of Paris, when he was a young, up and coming politician.
For Sarkozy, everything depends on the political atmosphere once the current crisis is over. Will it be a security-oriented debate where the outgoing president is at his best and his Socialist rival on the defensive? Or will it be about values, about the cohesion of the French society, where Sarkozy and his Le Pen-like statements will be at risk?
We don't know yet the motivations of the cold-blooded killer of Toulouse and Montauban. What is certain is that he has succeeded in disrupting the election campaign, taking candidates away from the central issues of unemployment, the fate of the euro and the future of nuclear energy, and taking it into uncharted territory.