DeLillo said he wanted to do justice to historical likelihood and so he surmised in his novel Libra: When the Secret Service heard the tape, they prevailed upon the President’s men to cancel the motorcade scheduled for Miami. Kennedy traveled by helicopter from the airport to a downtown hotel, where he spoke to a group of journalists. Nicholas Branch has two theories about this incident. One, T. J. Mackey leaked news of the plot either directly to Milteer or to people in his circle. It’s a fact that Mackey had connections in the intelligence unit of the Miami police and it’s possible that he knew Milteer was being monitored. Milteer, a sixty-two-year-old Georgian, was known to be involved in violent resistance to integration. Two, it was Guy Banister who told Milteer about the Miami plot and unwittingly ruined the operation. (The Secret Service did not forward details of the taped conversation to agents responsible for the President’s safety in Dallas. The FBI questioned Milteer superficially after the assassination.) Branch also has a theory about the Oswald doubles who were active for almost two months, mainly in and around Dallas but also in other Texas cities. He thinks Mackey devised the scheme principally to occupy Alpha 66, to get them so deeply entrenched in rigid arrangements and setups that they wouldn’t be able to adjust when the Miami facade folded over in the first breeze. Joseph Milteer had spoken of the difference between countdown and go. Mackey wanted to be sure that Alpha was stuck in countdown. He would be sitting on go.
One guys grandiose story with no evidence of any kind to establish credibility is irrelevant. As facts and evidence have proven: Oswald acted alone and you have yet to refute that fact
Chicago was also chosen as a city where JFK could be killed and was only switched at the last moment. http://abc7chicago.com/archive/9315215/