For once, the polls and the pundits were right. In France's center-right presidential primary run-off on Sunday, François Fillon smashed his challenger Alain Juppé. An afterthought in the race only a few months ago, Fillon is now the favorite to be the next president of France. It's an astonishing rise, and one that portends some interesting developments in French politics.

The first thing to say is that Fillon has upset everybody's calculus for the presidential election.

With French President François Hollande's popularity plumbing historic single-digit lows and the left in disarray, this election was always going to be a brawl between the various factions of the right and center. But the conservative choice was supposed to be between the National Front's Marine Le Pen and either the moderate centrist Alain Juppé or former President Nicolas Sarkozy. National Front was delighted: Juppé left a wide-open space to his right and Sarkozy's track record and abrasive personality turn off large swaths of the population. But Fillon disrupts this dynamic.

His great asset is that he looks like a candidate who can unite the various fractious factions of the French right. His positions are conservative enough to appeal to the right without being unacceptable to most of the center. Meanwhile, his track record as an establishment politician and his soft demeanor is soothing to moderates who would be turned off by similar positions coming from Sarkozy.

Emmanuel Macron, the dashing center-left former economy minister who recently announced his candidacy, looked to grab center-right voters who want free market reforms but are turned off by Sarkozy; now Fillon offers those same reforms without most of the populist rhetoric that turns off centrists. Various motley centrists, such as perennial presidential candidate François Bayrou, will almost certainly try to run in the center lane while painting Fillon as a dangerous extremist, but, justly or no, it's simply impossible to watch Fillon for five minutes on TV and believe he fits the type. He seems like a Teflon candidate, just hardline enough that he cannot be portrayed as too soft, just soft enough that he cannot be portrayed as too hardline.

His biggest enemy now may not be any candidate or party, but the Favorites' Curse that seems to be affecting politicians the West over. Restive voters tend to turn out against whoever has been anointed as the next person-in-charge by the polls and the media.

But even if Fillon falters, it's already clear that French politics has changed.

Fillon, previously a moderate, seems to have adopted an identity very close to a mainstream U.S.-style conservative, even as the rise of Donald Trump has thrown classical American conservatism into an identity crisis. Fillon openly proclaims his admiration for Margaret Thatcher in a country where free market ideas are anathema. During the primary, he published a book on what he called "Islamic totalitarianism," a term popularized by foreign policy neoconservatives in the wake of 9/11. And, most strikingly, he openly catered to the Catholic vote, in a country where religious expression in public is taboo, and where "the Catholic vote" has been an oxymoron since the 1905 law separating church and state.

Any French political watcher would have called this strategy a loser — and indeed it looked like a loser in the polls, until nominal Catholics started turning out as Catholics and delivered Fillon a smashing upset in the primary's first round.

In the second round, the 71-year-old Juppé tried an old trick of French politics: la diabolisation, i.e. painting your opponent as an extremist. It's a tactic that exists everywhere but is so common and devastating in France that it has a name. So Juppé argued Fillon would overturn abortion laws (even though Fillon has consistently said that while he is personally opposed to abortion, he would not change laws), and that Fillon is anti-gay (Fillon has consistently said he would not overturn France's same-sex marriage law, though he would restrict adoption to opposite-sex couples). As can be seen from Sunday's results, la diabolisation not only failed, it backfired badly.

This primary heralds the potential not only for a U.S.-style conservative moment in French politics but for a decisive shifting of the so-called Overton Window, the implicit matrix in a society for what you can talk about and not talk about in public. That's more exciting than horse races.