The two pillars of Sarky's victory - a popular appeal to racist xenophobia amplified by media mogul support - were already evident in the first round:
As Interior Minister, Sarkozy has talked tough against those of North African origin - i.e. Muslims. He sought to garner votes from extreme right National Front candidate Jean-Marie Le Pen. Just before the first round, Sarko promised white French colonists who fled Algeria, most of whom are Le Pen fans, never to sink into the demagogy of apologising for colonialism. Sarko's gamble paid off: nearly seven points of his vote - more than his margin over Royal - came directly from Le Pen, who got 16.95 per cent in 2002, against 10.44 per cent in 2007. Le Pen voters recognised similar ideas about that kind of people, as John Howard would put it...I've already discussed how Big Media helped Sarky get elected.
The essayist Diana Johnstone calls him "Sarko the American" and says his "Three Rs" are Racaille (scum, i.e. Muslims), Religion and Repression. In much of the mass media, however, he benefits from his notorious vindictiveness: he has got many media magnates to punish editors and reporters who crossed him.
My latest thoughts on Sarky's victory are here: Global Corporate Control Just Took Another Big Step Forward.