A direct-election runoff for president is fundamentally very simple. There’s only one number that matters. So, in a developed country, where pollsters know what they’re doing, there’s not much excuse for getting it wrong — unless it’s exceptionally close.

This one wasn’t. As soon as the polls closed at 4am this morning, eastern Australian time (8pm in Paris), the TV networks broadcast the exit poll results, showing the centre-right’s Nicolas Sarkozy the winner on 53%. A few minutes later, his Socialist rival Segolene Royal, still smiling, graciously conceded defeat.

When the official results were completed, they confirmed the exit polls almost exactly: Sarkozy finished with 53.06%, on a turnout of 84%, the highest since 1988.

Evidently Jean-Marie Le Pen’s call for “massive abstention” was not a success.

Sarkozy, claiming victory, looked genuinely humbled by the moment, but he quickly got into his stride, promising to “be the president of all the French people”, pledging his support for European Union, and offering friendship to America while telling them it was their duty to lead the fight against global warming. It was somewhat odd, but also typically French, to hear a victor from the right say that “France will be on the side of the oppressed of the world.” (The BBC has an edited translation of his speech here.

Despite all the commentary on the stark choice that the French faced, the truth is that Sarkozy in office is unlikely to be nearly as radical as his opponents fear and some of his supporters hope. Although (as Royal also admitted) France needs economic reform, things are not so dire as to create a demand for change at the price of social chaos.

There have already been some riots in response to the result, and if Sarkozy pushes reform too far there will be much more. I suspect he is intelligent enough to understand the limitations of his position, and before long he will look much more like Jacques Chirac (who also in his day was tagged as a radical) than Margaret Thatcher.

The other important thing to remember is that a French president, although more than a figurehead, is not a head of government. To implement his program he needs a majority in the legislature, which will be elected next month, and the strength of the centrist vote makes that an uncertain prospect.