The New York society scene was set by the Rockefellers and the Astors with a tradition of civility, philanthropy and the arts at its heart. Even those who make money the rough way — especially them — adopt this genteel facade. Michael Bloomberg is the quintessential emblem of this model and Donald Trump is the quintessential raspberry to it. One top New York foundation official who requested anonymity — many people will only speak anonymously about the Trumps and the Clintons, because both clans are known to be vindictive — notes that “in the community of plutocrats and superachievers who come to New York, Donald Trump is seen as persona non grata. He’s not a civic leader.” New York, this person says, is a place where private-equity C.E.O.s like Henry Kravis and Stephen Schwarzman see themselves making commitments to the public good. Their status doesn’t come only from being in charge of powerful corporations. “It also comes from some attachment to a hospital or university or cultural center. Trump was never part of that ecosystem.” When the tightfisted Trump hosts a charity event for veterans or a charity golf tournament, it is dismissed as something to polish the Trump brand. Trump has turned off many people in the worlds of real estate, banking and law with his strong-arming, fee-shaving or stiffing, bankruptcies and litigiousness. “Most real estate guys won’t go near him,” a leading New York financial executive says. “You lie down with dogs, you get up with fleas.”

Trump thumps his chest about money, acting as if he’s Bloomberg-wealthy, while the Clintons pretend they have less than they do. Trump wants to belong, to get more legitimacy by elbowing his way into the power crowd, while the Clintons passed that threshold of belonging after two terms in the White House. A top media mogul dismisses all three as outsiders: “No one here thinks of the Clintons as New Yorkers, and Donald is a bridge-and-tunnel person. He’s always been a poseur in New York.”

Trump realized that golf was his entree if he wanted to pal around with Bill Clinton, whom he considered a kindred spirit in some ways — a great man who attracted jealous haters. “Bill is kind of Trump with a dictionary,” one author who has written about New York real estate says. Trump had been obsequious in trying to lure Ronald and Nancy Reagan to his business empire, and tried just as hard with the Clintons. He happened to have his own country club with a golf course in Westchester, which he bought out of foreclosure in the late 1990s. He closed the club in 1999 to redevelop it from top to bottom and reopened it as Trump National Golf Club in 2002. It was six miles from the Clintons’ house, and Trump could play with him, ingratiating himself further by hanging photos of Bill on the wall. As of June, Bill still had a locker at Trump’s golf club.

Trump once told me that he rebuilt the club, in part, because he knew Bill Clinton would need a place to play. As Don Van Natta Jr., an ESPN senior writer, wrote in his book about presidents and golf, “First Off the Tee,” Trump enjoyed playing with the ex-president. “He’s got a lot of golf talent, but he really likes those mulligans,” Trump told Van Natta. “If he misses a shot, he wants to take another crack at it. It’s like life.”

Trump greased the wheels of his relationship with the ex-president and the senator, giving the Clinton Foundation a $100,000 gift from his own foundation. According to “Trump Revealed,” by Michael Kranish and Marc Fisher, Trump donated to Hillary’s Senate war chest six times between 2002 and 2009, for a total of $4,700, and between 1999 and 2012, he switched his registration among the Republican, Democratic and Independence parties seven times.