On the first freezing winter day of 2026, surrounded by thousands of cheering New Yorkers and progressive Democratic allies, New York City Mayor Zohran Mamdani pledged to tell a 'new story of our city'.

'City Hall will deliver an agenda of safety, affordability, and abundance - where government looks and lives like the people it represents,' he told the crowd in his inaugural address.

It was the same message that propelled the 34-year-old Democratic socialist to an unexpected electoral victory in November. His pitch to lead the most expensive US city included big changes, such as universal childcare, free public buses, and city-run grocery stores.

But the mayor is likely to encounter several challenges in trying to deliver on these promises, and he'll need to keep on board other important political stakeholders - beginning on his first full day in office.

1. Paying for policy promises

Mamdani's lofty policy platform has centred on cost-of-living issues, including freezing rent hikes for subsidised housing units and providing universal free childcare.

While he can accomplish some goals independently, funding many others may prove complicated, especially as the city faces budget shortfalls. Mamdani has suggested raising taxes on the wealthy to generate billions for these initiatives, however, he will need support from state government to implement such changes.

2. Avoiding White House intervention

President Donald Trump's previous attacks on Mamdani as a 'communist' mayor threaten to overshadow the new administration. Yet their initial meeting was surprisingly amicable, though tensions may arise over policies like immigration.

3. Getting business leaders on board

Mamdani's primary win sent shockwaves through the business community, with some leaders expressing concern over his progressive agenda. However, his outreach efforts may help bridge that gap, as influential business figures like JPMorgan Chase's Jamie Dimon have extended their support.

4. Addressing public safety

Mamdani aims to tackle crime and safety in New York City, a challenge faced by all city leaders. With crime rates dropping post-pandemic, he hopes to innovate with programs focused on community safety and mental health support. The credibility of his approach will be pivotal in shaping public perception and support.