Zohran Mamdani, the newly elected mayor of New York City, is notable in many ways. He will become the city's youngest mayor since 1892, its first Muslim mayor and its first mayor born in Africa.

That alone makes his victory over former Governor Andrew Cuomo and Republican nominee Curtis Silwa remarkable.

But more than that, he represents the kind of politician that many in the Democratic Party's left have been seeking for years.

He is young and charismatic, with his generation's natural comfort with social media.

His ethnicity reflects the diversity of the party's base. He hasn't shied away from a political fight and has proudly espoused left-wing causes - such as free childcare, expanded public transportation and government intervention in free market systems.

Mamdani has also shown a laser-like ability to focus on the kind of core economic issues that have been a priority for working-class voters who have drifted from the Democratic Party recently, but he hasn't disavowed the left's cultural principles.

But critics have warned that such a candidate is unelectable in broad swathes of America - and Republicans have gleefully held the self-avowed socialist up as the far-left face of the Democratic Party. Still, on Tuesday night in New York City, he was a winner.

By running against and defeating Cuomo, a former New York governor who is himself the son of a governor, he has vanquished the entrenched Democratic establishment viewed by many on the left as woefully out of touch with their party and their nation.

Because of this, Mamdani's campaign for mayor has generated voluminous media attention, perhaps more than a municipal election, even one for America's largest city, deserves.

It also means that, as mayor, his successes - and failures - will be closely scrutinised.

Twelve years ago, Democrat Bill de Blasio won his race for mayor on a platform of addressing New York City's economic and social inequalities. Like Mamdani, Americans on the left had high hopes that his administration would provide a national example of effective liberal governance.

De Blasio, however, departed office eight years later widely unpopular and with a mixed record of achievements as he struggled with the limits of his mayoral power to implement new policies.

Mamdani will have to grapple with those same limits - and those same expectations.

New York Governor Kathy Hochul, a fellow Democrat, has already said she opposed raising the kind of taxes necessary to fund Mamdami's ambitious agenda.

And even with sufficient funding, Mamdani would not be able to implement programmes unilaterally.

But all that is a problem for a later date. For now, Mamdani will need to set about the task of defining himself on the public stage - before his opponents do.

While his campaign has generated national attention, he is still a blank slate for much of America.

A recent CBS poll indicated that 46% of the American public were following the New York mayoral election "not closely at all". That provides both an opportunity and a challenge for Mamdani and the American left.

Conservatives from President Donald Trump down will be trying to paint the newly elected mayor as a socialist menace, whose policies and priorities will bring ruin to America's largest city and present a danger if embraced by the nation as a whole.

They will amplify every stumble and highlight every negative economic indicator or crime statistic.

Trump, who has a personal connection to New York, is sure to welcome a political tussle with Mamdani, and he has a wealth of ways to complicate life for the new mayor.

The opportunity for Mamdani, however, is that he is not burdened by his past, which his political opponents unsuccessfully tried to wield against him during the campaign.

When he is inaugurated in January, he will have the chance to build his political reputation from scratch. And if Trump does feud with him, he will only give Mamdani a larger platform to work on.

His political talent and abilities have gotten him this far, which is no small feat. But that is nothing compared to the tests that await him in the years ahead.