Democratic Socialist Zohran Mamdani has opened a commanding lead in the New York City mayoral contest, according to a Siena College survey of registered voters conducted 4-7 August. The poll shows Mamdani at 44%, 19 points ahead of former governor Andrew Cuomo at 25%, with Republican Curtis Sliwa at 12% and incumbent mayor Eric Adams, now running as an independent, at 7%. Mamdani’s net favourability in the city stands at +14, while Cuomo registers –17. Betting markets have moved sharply in the same direction. Data from Polymarket on 13 August place Mamdani’s probability of victory at 82%, up from just 5% in May, underscoring investors’ belief that the race is tilting decisively toward the 33-year-old state assembly member. Wall Street is adjusting to the prospect of a far-left mayor. JPMorgan Chase Chief Executive Officer Jamie Dimon held what was described as a “friendly” phone call with Mamdani after previously labelling him a Marxist, part of a wider series of meetings between the candidate and executives including Point72’s Michael Sullivan and developer Jed Walentas. Business leaders are pressing Mamdani on proposals such as rent freezes, higher corporate taxes and publicly run grocery stores. Within the Democratic establishment, reactions are mixed. House Minority Leader Hakeem Jeffries has declined to endorse the nominee and said questions about Mamdani’s use of a rent-controlled apartment are “legitimate” and must be addressed. By contrast, figures close to former President Barack Obama have been in contact with the campaign, signalling interest in the insurgent candidacy. On the trail, Mamdani’s “Five Boroughs Against Trump” tour has drawn both supporters and detractors. A rally on Staten Island ended with the arrest of activist Scott Lo Baido, who confronted the candidate and was charged with disorderly conduct and related offences. Mamdani said the incident would not alter his campaign schedule. The same Siena polling wave also tested the statewide gubernatorial race, finding Democratic Governor Kathy Hochul ahead of Republican Representative Elise Stefanik by 45% to 31%, with 20% of respondents undecided.