The once-gritty embankments along the wide sweep of the Garonne River are teeming with runners and bikers against a city glistening in the morning sun. The man responsible for Bordeaux's makeover, including a tramway linking scruffy immigrant neighborhoods to the city's elegant center, promises to do the same thing for France.

But today Mayor Alain Juppe, who once seemed poised for the presidency, is running a distant second in France's conservative primaries. The man to watch ahead of Sunday's runoff is dark horse candidate Francois Fillon, who leads him by nearly 16 points.

Along with his traditionalist credentials and free market platform, Fillon's clean slate appeals to many in a county weary of scandals. Juppe, by contrast, was handed a suspended prison sentence more than a decade ago for his implication in a corruption case.

"Too old, too many issues, too close to Muslims," one Bordeaux taxi driver, summing up her personal misgivings about 71-year-old Juppe, told DW.

Sunday's vote will be closely watched. With the ruling Socialists weak and divided under Francois Hollande's unpopular presidency and the surging far right National Front party still anathema to many voters, many observers believe the victor will likely be France's next president.

"The separations are very porous, they're plaster rather than cement," Jean Petaux, a political scientist at Sciences Po Bordeaux, told DW, describing a still-fluid voter assessment of the two candidates. Still, a spectacular Juppe rebound would be "exceptional," he believes.

Winning the debate

Indeed, it was Fillon who emerged the winner of Thursday's televised debate between the two finalists. A post-debate poll published by BFMTV found six out of 10 French judged him more convincing as he outlined his economic platform and clashed with Juppe over a multiculturalism and relations with Russia.

Both men are former prime ministers who have spent decades in politics. Both are calling for ending the 35-hour workweek, slashing the public sector workforce, reducing taxes and spending and increasing the retirement age. But Fillon's suggested cuts go deeper, his pro-business stances are more affirmed.

Fillon also supports ending Europe's hard-line stance against Russia and negotiating with Syria's leader Bashar al-Assad in defeating the "Islamic State," both of which Juppe opposes.

Yet it is their social views, perhaps, where the two men contrast most sharply. Juppe's campaign is themed on a nation with a "happy identity" that embraces multiculturalism. Indeed, his support for project to build a major mosque in Bordeaux and his close ties with the city's respected imam, Tareq Oubrou, made him the target of a virulent "Ali Juppe" smear campaign on the Internet.

A threat to the far-right?

By contrast, Fillon's emphasis on his Catholic roots and family values has resonated among French worried about militant Islam and immigration. So has his call for a law banning the little-worn Muslim burkini on public beaches.

"He defends a more radical vision of change that implies, beyond reforms, to reconsider intellectually the French model, with its egalitarian and 'multicultural' vocation,'" France's conservative "Le Figaro" said of Fillon. In an editorial, the newspaper describes the stakes for 62-year-old Fillon as nothing less than an ideological battle.

Fillon not only appeals to traditional right wing supporters from middle class, urban backgrounds, analyst Petaux said, but also those from rural France and the country's gritty suburbs who might normally vote far right.

"Francois Fillon is a lot more of a problem for the National Front than Alain Juppe," Petaux said. "By defending traditional French values, and for a return to a certain moral order, for the Christian roots of France and Europe, he's pretty much poaching votes in National Front territory."

Still Juppe argues he is best positioned to capture the center and the left. And in largely leftist Bordeaux, where he enjoys widespread popularity, his supporters are still hopeful.

"He's a real visionary for this city and for the country," said Juppe's deputy-mayor Anne Brezillon as she passed out flyers by the river.

Two prime ministers

Like his city, Juppe has also undergone a makeover. Once one of France's most unpopular prime ministers in the 1990s, he rebounded after his corruption sentencing and was reelected mayor of Bordeaux in 2006. He went on to become defense and then foreign minister under former president Nicolas Sarkozy, who was ousted in the first round of conservative primaries last week.

"I think what Alain Juppe did for Bordeaux he can do for France," student Florian Ciret, who describes himself as a "disappointed leftist" who will back Juppe on Sunday, told DW. The vote is open to all French agreeing to pay a small fee and sign a statement subscribing to "Republican values."

Fillon, too, has come in from the wild. As prime minister between 2007 and 2012, he was largely overshadowed by his hyper-energetic boss, Nicolas Sarkozy. He later lost a bid to lead his center-right party. Until a few weeks ago, few believed he could score well, much less emerge the first-round winner, with more than 44 percent of the vote.

Whoever captures the runoff must take on the National Front's popular leader, Marine Le Pen. She is hoping for an upset victory similar to that of US President-elect Donald Trump, whom she supports. Many experts believe she may well win the first round of elections next April, but fail to prevail in the second.

For Juppe, this will likely his last shot at the presidency. If elected, he vows to serve only a single term.

"He's been a good mayor, he's done a lot for Bordeaux," said another leftist resident Michel Garcia, who cannot bring himself to vote for the right. "He could also be a good president. But he's going to have a hard time winning."