Every month, Leonard Steinberg, a leading broker at Douglas Elliman who has been responsible for more than $2 billion in residential real estate transactions, largely in downtown Manhattan, publishes something called The Luxury Letter. The report combines various listings — for $9 million duplexes in Chelsea, for a $44.9 million “loft mansion” in TriBeCa — with Mr. Steinberg’s insights on the high-end property market and the city more generally. Titled “Mayoral Issues: A Tale of Two Cities?” the October editor’s note recommended that the city’s presumptive next leader, Bill de Blasio, devise a “worst tenants” list, and cautioned those who criticize Michael R. Bloomberg that a mayor’s role is to be “effective C.E.O. of the city, not ‘best friend.’ ”

A champion of the Teterboro class, a man we imagine having greeted Occupy Wall Street with a call for Rigaud candles and fumigation, Mr. Steinberg late last month was surprised to be attending a fund-raiser for Mr. de Blasio. The impetus was a call from the real estate impresario Steve Witkoff, developer of the luxury West Village condominium complex 150 Charles, which has a $35 million penthouse and which Douglas Elliman represents. Mr. Witkoff was holding an event for Mr. de Blasio in his Upper East Side home. “I thought if he’s met Bill de Blasio and formed a personal impression, I want to know more,” Mr. Steinberg told me. After spending some time with the candidate, he was moved to make a donation.

In their conversation, Mr. Steinberg shared a long-held obsession with Mr. de Blasio — the seemingly arbitrary way tax assessments are determined, leaving some property owners to grossly overpay and some to underpay. “I said, ‘If you are the mayor of fairness, you have to do something about this,’ ” Mr. Steinberg recounted. “And he said, ‘Leonard, I’m definitely going to look into this.’ He gave me a credible look in the eye, an I’m-going-to-do-something-about-this look, not a political BS look.”

The exchange reflects Mr. de Blasio’s potentially dubious gift for ecumenical connection. The idea that a de Blasio administration would alienate the wealthy, that the wealthy would revolt against relatively slight tax increases and move to Miami, that they would endure any significant marginalization in the narrative of the city, seems to be losing its currency. Mr. de Blasio has reached out to the real estate community; there have been several industry fund-raisers for him. It could hardly be otherwise. “People talk about Wall Street, but even before ’07, ’08, it was really real estate that was the A.T.M. of New York,” Steven Spinola, president of a powerful lobbying group, the Real Estate Board of New York, told me.