He pledged to raise taxes on the rich, which helped Democrat Bill de Blasio win the mayoralty of New York, one of America's most expensive cities.
But that pledge also has some worried that higher-income New Yorkers will flee the city to seek lower taxes in the suburbs.
"If there is a major change in tax policy, it will definitely impact the real estate market. There's no question about that," said Dolly Lenz who has brokered more than $8 billion in Big Apple deals.
But she does not think such a change will happen.
"He will not kill the goose that laid the golden egg," Lenz said of de Blasio, who has championed affordable housing.
Over in northern New Jersey, real estate agent Ondine Lewitinn said that her phone is already ringing. Former clients who bought properties in Manhattan are now asking about Alpine and Englewood Cliffs, N.J.
"They are afraid that things are going to change," she said. "They are afraid the taxes are going to be higher."
(Read more: NYC's de Blasio a foe of Wall Street? Not likely)
That fear has not turned up in Manhattan sales figures, however. In fact just the opposite.
""If people are leaving the city in droves, it must be the next shift. If there was a panic, it wasn't reflected in actual consumer behavior.""
Sales of condominiums and co-ops in the borough were up 30 percent in the third quarter year over year, according to Douglas Elliman Real Estate. That was during the heat of the mayoral campaign.
Sales are now at the highest level since the last peak, in 2007, and the second highest in 20 years. Days on the market are down nearly 54 percent, showing big demand for little inventory.
(Read more: Goldman, SAC among de Blasio's Wall Street backers)
"If people are leaving the city in droves, it must be the next shift," said Jonathan Miller CEO of Miller Samuels. "If there was a panic, it wasn't reflected in actual consumer behavior."
Miller also pointed to huge new residential development, not just in Manhattan but across the five boroughs. There is clearly no investor concern about any exodus. If people are leaving the city, Miller said, it is because Manhattan is getting more and more expensive. International investors have fueled the high-end housing market and that wealth is trickling down even to mid-range properties.
Higher taxes may hurt the super-rich, but they already know they are paying a huge premium to live in Manhattan, to own exclusive residences and enjoy a certain lifestyle—one that comes with a corresponding price.
—By CNBC's Diana Olick. Follow her on Twitter