For a good part of his life Giancana was under constant FBI surveillance. This surveillance extensively documents the relationship between Giancana and Sinatra. Sinatra told IRS investigators in 1959 that he met Giancana at the Fontainbleu Hotel in March 1958. Sinatra always maintained that he and Giancana were friendly, but not close, and that they had no business relationship. The FBI surveillance shows this to be a lie.

Sinatra played a kind of court-jester role for Giancana, giving command performances when asked. Sinatra also arranged command performances by other entertainers for Giancana.

As for the business relationship between Sinatra and Giancana, nothing was ever clearly proven, however Sinatra’s association with Giancana did prove to be a major liability for the star in the fall of 1963, when Sinatra acted as a front for Giancana’s ownership of the Cal-Neva Lodge in Lake Tahoe, adding to Sinatra’s nine percent in the Sands Hotel in Las Vegas. To own a stake in a Nevada gambling establishment, an individual had to have a state gambling license, which Sinatra had obtained in 1954. This license allowed him to buy into the Cal-Neva Lodge. However, the state of Nevada maintained what was called the Nevada Black Book, which contained the names, photographs and criminal records of 11 men who were forbidden from entering any casino in the state. Casino owners who allowed any of these people into their establishments risked losing their licenses. Sam Giancana was one of the 11, so his ownership of any gambling interests there had to be covered up.

In 1960 Giancana made arrangements to buy the Cal-Neva Lodge, located at the north end of Lake Tahoe exactly on the California-Nevada border. The owners of record would be Frank Sinatra, Hank Sanicola (an old friend and business partner of Sinatra’s) and Dean Martin. At first Sinatra owned one-third of the hotel, but within a couple of years his ownership had risen to over half and Dean Martin had dropped out in favour of Sanford Waterman, not wanting a direct link to the mafia. Paul "Skinny" D’Amato, one of Giancana’s lieutenants who had "worked" the West Virginia primary for John Kennedy, took over day-to-day operation of the club.

The Cal-Neva Lodge, with its unique location half in California and half in Nevada, was perfect for Giancana’s purposes. He visited the club regularly (when he would admit visiting he claimed that he always stayed on the California side) for trysts with his mistress, Phyllis McGuire, meetings with other mobsters or Sinatra’s wild parties.

Giancana’s ownership of the hotel was confirmed by the FBI, which recorded a conversation between Giancana and Johnny Roselli, in which Giancana said, "I am going to get my money out of that joint (Cal-Neva) and end up with half of it with no money."

During a singing engagement at the Cal-Neva by the McGuire Sisters, Phyllis McGuire, Sam Giancana, Frank Sinatra and Victor LaCroix Collins, road manager for the McGuire Sisters, became involved in a brawl in Giancana’s bungalow. FBI agents witnessed the fight and informed the Nevada State Gaming Commission. This was the last straw and in August 1963, Ed Olson, chairman of the commission started an investigation with the goal of revoking Sinatra’s gaming license, and on Sept. 11, 1963, the Nevada Gaming Control Board did just that for allowing Chicago crime boss Sam Giancana to visit the Cal-Neva Lodge. Sinatra agreed to surrender his license and sell his interest in the Sands.

On February 10, 1961, FBI Director J. Edgar Hoover sent a pointed memo to United States Attorney General Robert F. Kennedy, regarding singer Sinatra’s extensive connections to organized crime figures. Special agents had been keeping tabs on Sinatra since 1947, when he took a four-day trip to Havana and was seen on the town with a group of powerful Cosa Nostra members who had gathered there for a mob conference. Hoover’s message to the attorney general was: “Look who your brother the president has been hanging around with.”

In the memo Hoover gave a précis of Sinatra’s alleged criminal background prior to his Mafia involvement. Hoover wrote that in 1944, according to “an anonymous complaint,” Sinatra had paid $40,000 to get out of the draft. The FBI director went on to point out that Sinatra had “reportedly been associated with or lent his name to sixteen organizations which have been cited or described as communist fronts” even though the bureau’s investigation never uncovered sufficient evidence to prove that Sinatra was ever a Communist Party member himself.

Hoover then ticked off Sinatra’s criminal associates, including Joseph and Rocco Fischetti, who were cousins of Al Capone; New Jersey crime boss Willie Moretti; James Tarantino who was himself an associate of gangster Benjamin “Bugsy” Siegel; Mickey Cohen; and reigning Chicago boss Sam Giancana. According to Hoover, in the summer of 1959, Sinatra allegedly hosted a nine-day, round-the-clock party at the Claridge Hotel in Atlantic City where Chicago wiseguys rubbed elbows with top East Coast mobsters. Hoover even quoted a female informant who had met Sinatra and Joe Fischetti at the Hotel Fontainebleau in Miami and believed that the singer had “’a hoodlum complex.’”

The record shows that Sinatra performed in clubs and theatres controlled by the Mafia and Giancana, made investments with them and used his status as a celebrity to make requests on their behalf—all the way to the Oval Office in one instance. He hosted men of honour at his home, at his hotels, even at his mother’s home.

The early ‘50s were hell for Sinatra - his popularity slipped; he lost his singing voice for a time and his career just about hit bottom. Only his old mob pals would hire him for their clubs. His career was at an all time low, whilst wife’s Ava Gardner, was on the rise. The pair separated in 1953, seeing him fall into a deep depression.

Throughout his life, Sinatra sought out alliances with powerful men, both in the legitimate and illegitimate worlds. In the early ‘60s, his power complex brought him into the ultimate circle of power, that of the newly elected president of the United States, John F. Kennedy. Sinatra was close to Giancana, and he wanted to be closer to Kennedy. Behind the scenes Giancana shared that desire because he wanted what no Mafia capo had ever achieved—access to the Oval Office.

In the 1960 presidential election, Kennedy was running against the sitting Republican vice president, Richard Nixon. The Kennedy campaign had pinpointed certain areas of the country that could go either way in the election, and they need help securing these areas. The word was passed from Kennedy’s father, Joseph Kennedy, to Sinatra: “Ask your “friend” in Chicago to help us with West Virginia and Cook County, Illinois.” Giancana was willing to oblige, delivering his home turf as well as West Virginia where his outfit had enough sway to influence the election. When Kennedy won, Giancana expected the new administration to show its thanks by getting the feds off his back.

At Giancana’s suggestion, Sinatra introduced Kennedy to an ex of his, a lady named Judith Campbell, sparking an affair between the two. At the same time Giancana started dating Campbell, not because he desired Campbell but because he had a habit of wooing the wives and girlfriends of men he wanted to control to gain inside information and show that he could have anything his target held dear.

Sinatra was indeed out of the Washington loop as he was hated by Jackie, hardly ever invited to the White House and if he was he was only ever asked to use a side door, however Kennedy did call Sinatra on an irregular basis, but this was mostly to cover the President's favourite topic, Hollywood gossip.

The Kennedys had been keeping their distance from Sinatra for some time before they ceased all ties, in part due to the singers often erratic public, and private, life.

Kennedy’s advisors rightly felt that Jack should not be sharing a bed with Judy Campbell, a woman also dating a top mobster, particularly when the attorney general was working so hard to rid the country of organized crime. The president dumped Campbell and distanced himself from Sinatra. Dropping Sinatra wasn't a tremendous loss for the White House, they had gotten what they wanted out of Frank, and, if they ever needed him again, they knew that all they would have to do would be to snap their fingers and he'd come running. The Kennedys justified dropping Sinatra, by having one of Robert Kennedy's employees at the Justice department suddenly "discover" that Sinatra had ties to organized crime and humiliated him publicly before giving him the axe completely.

With Sinatra out of Kennedy’s good books, wiretaps revealed Giancana’s disappointment and his low regard for the singer. When it became clear that Sinatra wasn’t going to get him what he wanted, the mobster had no use for him.

Stories and rumours about Frank Sinatra abounded; people thought - and still do today - that he was one of the key men behind the Mafia. In fact, though, it would appear that the mob never did much for Sinatra, and Sinatra never did much for the mob - not that anyone has ever been able to document, anyway. Indeed, when Sam Giancana associate Johnny Formosa suggested (in another FBI wiretapped conversation) that Giancana "take out" Sinatra, Giancana wasn't interested. "Let's show 'em," Formosa pushed. "Let's show those . . . Hollywood fruitcakes they can't get away with it as if nothing's happened." Giancana said, "No. I've got other plans for them." A better-thought-out, better-orchestrated "hit" perhaps? Strangely, no hit was made on any of the men in the Rat Pack.