‘A Love Fest’

Mr. Diamond, 80, met Mr. McCain when he was a former prisoner of war running for Congress in 1982. “I liked him right away because I respected what he went through in Vietnam,” Mr. Diamond recalled. When he got to know Mr. McCain and his wife, Cindy, Mr. Diamond said, “it became a love fest.”

Mr. Diamond was already a major player in Arizona real estate and Republican politics. A tenacious dealmaker who once visited a Mexican jail to close a sale with an inmate, Mr. Diamond had made a first fortune on Wall Street before turning his trader’s eye to the Arizona desert in 1965. He eventually became one of the state’s biggest landowners, picking up trophies that included the 12,000-acre Howard Hughes estate, stakes in two of Arizona’s professional sports teams, the Diamondbacks and the Suns, and, for a time, a Tucson television station.

Over the years, Mr. Diamond and his wife, Joan, visited the McCains at their ranch in Sedona, Ariz., and entertained them in their Tucson home and in the Bahamas, where Mr. Diamond sometimes keeps his 134-foot yacht, the Queen of Diamonds. In 2001, the two men attended a Yankees-Diamondback World Series game together. “He is just very, very good company,” Mr. Diamond said of Mr. McCain. “I knew all his people and the staff.”

Mr. Diamond and his family have given more than $55,000 to Mr. McCain’s campaigns (and more than $600,000 to other federal candidates). More significantly, the developer has collected (or “bundled”) hundreds of thousands of dollars in contributions from others, and is now serving as a national co-chairman of the finance committee for Mr. McCain’s current presidential run. In the spring of 2000, when Mr. Diamond was in the thick of the negotiations for his California deals, he traveled with Mr. McCain through the early Republican primaries. Mr. Diamond was on the campaign trail again this year.

In building his empire, Mr. Diamond said he had struggled with local elected officials over land use and zoning issues just like any other developer. “They are a pain in the ‘you-know-what,’ ” he said.

But associates say he revels in his ability to “work the system,” as his friend and sometimes partner, Stanley Abrams, put it: “Nobody is as connected as Donald.”

Mr. Diamond is close to most of Arizona’s Congressional delegation and is candid about his expectations as a fund-raiser. “I want my money back, for Christ’s sake. Do you know how many cocktail parties I have to go to?”