With his rightward move to siphon votes from Le Pen, Sarkozy had surged into a tie with Socialist Francois Hollande.
So it was that the left leapt with alacrity upon the massacre to charge that Sarkozy's new populism had created the climate in which such horrors against Jews and Muslims can occur.
So it was that the Times concluded that the nationalist turn in French politics might be halted, as it had in Norway after berserker Anders Breivik slaughtered scores of children last year.
What was happening should be readily recognizable to Americans.
When John F. Kennedy was assassinated by a Marxist in Dallas, the Goldwater right was charged with creating an atmosphere of hate that had made it likelier to happen there. When Rep. Gabrielle Giffords was shot by a crazed gunman who wounded a dozen others and slaughtered six, moral responsibility was laid at the feet of Sarah Palin.
Unfortunately for the French left, however, by Wednesday, the mass murderer had been identified as a homegrown Salafist jihadi and self-styled member of al-Qaida who had spent time in Afghanistan and Pakistan and been under surveillance for years by French intelligence.
Mohamed Merah was seeking revenge against Jews for the deaths of Palestinian children and against French soldiers for fighting in Afghanistan.
Le Pen seized on the news to blast the left, which had sought to blame the atrocities on her, and charged the French government with underestimating the Islamist threat and being lax on national security.
"It is time to wage war on these fundamentalist political religious groups who are killing our children," she said.
"The threat of Islamic fundamentalism has been underestimated. ... (I) have been talking about this for months and months, and the political class has rejected (me). Some are going to have difficulty explaining themselves, but I have a clear conscience."
With the killer precisely the type of individual the French right has said bears watching, Bayrou was hastily backtracking:
Politicians must "tackle the risk of importing into French society conflicts that are foreign to us or should be foreign to us."
As Europe's native citizens age and die and immigration goes on and on -- with 5 million Muslims already in France -- issues of national identity will bedevil Europe, even as they will bedevil us, forever.
In Toulouse we see clearly now not only the dark side of diversity but perhaps the future of the West.