Here. The young, the less educated, the less well-paid white- and blue-collar workers voted Front National. Abstainers stayed away from the polls because "voting doesn't change anything."
And as for the familiar charge of tous pourris--if the news about the false invoices used to drain tens of millions of euros from UMP coffers illegally to finance Sarkozy's campaign had been announced the day before the election rather than the day after, the FN might have gotten 30 percent instead of 25.
More details here.