Supporters of Martin Schulz, Germany's Social Democratic Party candidate for chancellor, react before a TV debate with German Chancellor Angela Merkel in Berlin, Sept. 3. (Fabrizio Bensch/Reuters)

There was a time only months ago when Martin Schulz — a high school dropout, former bookseller and political unknown to many in this country despite a decades-long career — seemed poised to pull off the German equivalent of Mission: Impossible.

After the blunt ex-president of the European Parliament became leader of Germany's center-left Social Democrats, the long-moribund party's popularity surged as backers clambered aboard "the Schulz train." Commentators excitedly speculated whether he could dethrone Angela Merkel after 12 years in power. Schulz himself vowed a "conquest of the chancellery."

But as that early-spring promise has met the reality of a late-summer German election campaign, it feels very distant.

With less than three weeks to go before voters choose their next government, Schulz and his party trail far behind in second place, while another Merkel term as chancellor — it would be her fourth — has taken on an air of inevitability. The Schulz train, once chugging ahead mightily, appears to be stalled on the tracks.

If Schulz’s party does lose, the defeat would mark the latest in a long run of setbacks for center-left parties that have their roots in the West’s industrial age but have struggled to define themselves in the 21st century.

But it would also reflect the particular challenge of vying against Merkel, a politician of the center-right who adopts many positions on the left, leaving little room for a coherent opposition.

It doesn’t help the SPD, as Schulz’s party is known, that it has served as Merkel’s coalition partner for two out of her three terms, including the current one.

“For 12 years, the SPD has more or less supported Angela Merkel’s policies,” said Gesine Schwan, a political scientist and Social Democratic veteran who was twice the party’s candidate for president. “It’s very difficult to show up now and say, ‘We want to do things completely differently.’ ”

That dilemma was on display one recent afternoon as Schulz attempted to rally the faithful in Leipzig, an eastern German city where the mix of university students, factory workers and government servants has long made it friendly turf for candidates of the left.

Schulz’s party — Germany’s oldest — got its start here as the General German Workers Association more than 150 years ago, and for 40 minutes on a warm August day, the stout, bearded and bespectacled Schulz punched the air and banged a lectern in the shadow of a 12th-century church where Johann Sebastian Bach once wowed the locals with his concertos.

The crowd applauded solemnly as Schulz invoked the SPD’s history in standing up to Hitler, a position that cost party leaders their lives. It cheered lustily as he berated President Trump for his equivocal response to white-nationalist violence in Charlottesville.

A poster of Germany's Social Democratic Party candidate for chancellor, Martin Schulz, is seen during an election rally in Leipzig, Germany, August 29. (Matthias Schumann/Reuters)

But when Schulz came to his critique of Merkel for not doing enough to ensure all Germans benefit from a growing economy, (“Our country isn’t fair. We want to change that.”), the best his audience of nearly 1,000 in the city’s central square could do was clap dutifully.

The muted response was in keeping with the overall mood in modern Leipzig, a city that feels economically prosperous but politically sleepy — much like the country overall. With a vibrant central shopping district that is full of organic smoothie joints and high-end home decor shops, some residents said they were reluctant to shake up what's working.

“Everywhere else is unstable. The U.S. is unstable. But what Angela Merkel does is keep this country stable,” said Christoph Von Radowitz, a 51-year-old who works for a company that makes electronic vehicles and who said he showed up at Schulz’s rally out of curiosity, not support.

Even those in the mood for change said they were unsure whether Schulz was the right agent.

Philip Fiedler, a 20-year-old student, said he disliked the close cooperation between Germany’s top two parties — “they’re like best friends” — and wants more debate. But he was willing to give Schulz a chance, if only for a somewhat unusual reason.

“He’s not one of the best speakers or one of the smartest minds,” said Fiedler, who said he was still deciding which party to support. “He’s just some normal person. But that’s interesting.”

That intrigue over Schulz’s regular-guy persona was in fact a big part of the surge in support he experienced in late winter and early spring, said Hendrik Träger, a University of Leipzig political scientist.

Schulz’s background as a school dropout from a working-class family, who has openly discussed his battle with alcoholism, makes him unusual in the relatively elite and highly educated world of German politics.

Schulz, 61, has been a politician for decades, rising from mayor of his small western German home town to member of the European Parliament and, up until late last year, its president. But he was relatively unknown on the German political scene when he took over as SPD leader early this year.

At first, Träger said, voters saw him as a fresh face with a background they could relate to.

“He was seen as the new Messiah, the big hope for the SPD and for Germany,” he said. “But when voters found out more about him, they learned that he was part of the establishment.”

As his biography lost its appeal, his message also failed to resonate. His background may be working class. But his proposals are hardly the left-wing populism of a Jeremy Corbyn or a Bernie Sanders.

“He talks a lot about social justice and social equality, but he’s very vague about it,” Träger said. “What, exactly, is supposed to be more just?”

Perhaps Schulz’s last chance to differentiate himself from Merkel before the vote was a nationally televised debate on Sunday where he largely pulled his punches.

That may be strategic: After the election, one of the likeliest scenarios is another grand coalition between Germany’s two largest parties, which would put Schulz in position to become one of Merkel’s top ministers.

But Schwan, the political scientist and SPD veteran, cautioned thatdoing another deal with Merkel would be suicide for a party already struggling to define its reason for being.

“If that happens,” she said, “then for the next 20 years, there’s no chance for the SPD.”

Luisa Beck contributed to this report.

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