Ahmed Aboutaleb attends a meeting at the U.N. on children and youth affected by violent extremism | Jewel Samad/AFP via Getty Images Opinion How the Dutch Left blew it Next year’s election is shaping up to be a fight between two right-wing leaders.

ROTTERDAM, The Netherlands — Ahmed Aboutaleb was giving a lot of Dutch politicians sleepless nights earlier this year. A moderate Muslim of Moroccan descent, the mayor of Rotterdam is the most popular politician in the country.

Had he entered the fray as his party’s candidate in the Netherlands’ national elections next March, it would have upended the race. Instead, Aboutaleb dropped out of the contest for his party’s leadership before it even began, retreating from national politics altogether.

Late last week, the Labour Party chose as its leader Lodewijk Asscher, a party stalwart who served as deputy prime minister in coalition with Prime Minister Mark Rutte, a fiscal conservative.

The Labour Party has struggled ever since it decided in 2012 to join Rutte in reforming the welfare state. The economy recovered, but Labour never did.

The dramatic turn of events underscores the threat facing the Dutch Left. Next year’s election is shaping up to be a fight between two right-wing leaders, with Rutte facing off against the populist agitator Geert Wilders.

Aboutaleb could have been the Left’s answer to the question of how to remain relevant as this traditionally liberal country enters the era of identity politics.

He really hit it home with Dutch voters in his response to the Charlie Hebdo attacks in January 2015. In an emotional interview on live television the day of the attacks, Aboutaleb urged radical Muslims “to just go away.”

The next day, during a Rotterdam solidarity march organized in response to the attacks, Aboutaleb stood out with a passionate speech in flawless French. Soon after, the White House invited Aboutaleb to a conference on terrorism, cementing his reputation as a national figure.

A devout Muslim, but opposed to all forms of religious radicalism and highly critical of immigrants who don’t respect secular Dutch values such as tolerance for homosexuals, Aboutaleb has become a leading proponent of a strong but measured response to issues like migration, religion and terror.

Even Wilders, an anti-Muslim firebrand with a habit of attacking both the Left and people of Moroccan descent, has referred to Aboutaleb as “a good man.” And Rutte has routinely mentioned Aboutaleb as an example of the opportunities the Netherlands gives people with a foreign background.

In many ways, Aboutaleb is the country’s best success story.

Having grown up in the Moroccan countryside, Aboutaleb arrived in the Netherlands at age 15, received a modest education and pulled himself up to the highest circles of society within a decade. He became a TV reporter, a government spokesman and a lobbyist for diversity.

He entered politics 12 years ago, as a member of the Amsterdam city government, before he was promoted to the national government and subsequently appointed mayor of Rotterdam — the birthplace of modern Dutch populism — in 2009.

With characteristic ease, Aboutaleb managed to create a political partnership with the heirs of Pim Fortuyn’s political movement. Fortuyn, credited with kickstarting the Dutch populist movement, and known for his controversial views on immigration and Islam, was assassinated in 2002.

And yet, despite his political successes and his popularity, Aboutaleb’s announcement on TV earlier this year that he was considering a run for Labour leadership was met rather coldly by the party establishment.

Dutch finance minister and Eurogroup chair Jeroen Dijsselbloem accused Aboutaleb of trying to force out Diederik Samsom, the party leader at the time.

Things got nastier behind closed doors, as the acting party leadership attempted to protect its position and accused Aboutaleb of placing his own ambition above party cohesion.

Aboutaleb, who values his image as a popular team player, decided not to risk his reputation with a bid for his party’s top job.

This is bad news for the Left’s political prospects. Aboutaleb would have provided Labour with its best weapon against Wilders’ brand of identity politics. Even as the party was picking its leader, Wilders was dominating the news after a Dutch court convicted him last week of inciting discrimination against Dutch Moroccans.

Wilders advocated for “fewer Moroccans” in 2014, a controversial statement that isolated him among the political class, but helped him gain popularity with voters.

Where Aboutaleb would have easily been able to adapt to the rise of identity politics — he is after all, a poster child for the success of liberal Dutch politics — Labour’s leadership has determinedly stuck to traditional, economy-driven politics.

The trouble is the policies that once made the Left a defining

force in the country, with 40 to 45 percent of the vote, have now left it ill-equipped to respond to the likes of Wilders and his impassioned pleas for a return to “Dutch” values.

Broadly speaking, the coalition government’s reforms have been successful: Growth is up, the deficit is nearing zero. But where Rutte has been able to portray these results as an achievement — “I can get things done” — Labour has struggled to convince supporters of its claim it saved the Dutch welfare state.

In the polls, Labour is down to less than 10 percent of the vote, now the country’s sixth or seventh largest party.

There is a fair chance Asscher will pull his party up in the polls. But, as a former Rutte deputy, his vulnerabilities are quite obvious, too.

Labour officials claimed Lodewijk Asscher, the newly elected party chief, will be able to turn this around with a moderate brand of identity politics. Asscher himself framed it as “progressive patriotism” — love of country as a left-wing agenda.

Asscher is critical of labor migration within the EU — and critical of the EU itself. He has argued ethnic and religious groups have to prove their loyalty to the Netherlands before they benefit from the welfare state, and has claimed to be the progressive alternative to both Rutte and Wilders on that score.

His personal ratings are above average, and insiders regard him as a smart and cunning player in Dutch politics.

There is a fair chance Asscher will pull his party up in the polls. But, as a former Rutte deputy, his vulnerabilities are quite obvious, too.

And even his most notable political success came with a heavy dose of irony. In 2006, Asscher won city elections in Amsterdam in one of the biggest ever local victories for his party.

Only one other politician collected more votes: his deputy on the ticket, Ahmed Aboutaleb.

Tom-Jan Meeus is a political columnist for NRC Handelsblad. He was awarded best political writer of the Netherlands in 2015.