I don't think it is at all unfair to use a dose of psychoanalysis here. What's changed in France? Economic conditions. The government is unable to force capital to play nicely in France and moreover new neoliberal policies instituted by previous governments has destroyed France's ability to weather the financial crisis. So then we have the Front National with it's old school right wing politics turning the issues around; it's not sacred France that has done wrong, it's the immigrants and the EU and everyone except the bankers and capitalists who actually caused this crisis.
In effect, Le Pen and her party are playing the old fascist game of point the finger at the Other, instead of Greedy Jews stealing from the Honest Christian [insert nationality here] it's Radical Fundamentalist Muslims (which are all of them) attacking the Sacred, Secular, and Free [insert nation here].
