Along with the CIA and Cuba, the next most well known theory is that the Mafia and Bobby Kennedy with Jack Ruby had something to do with the killing of the 35th President of the United States. The basic understanding of why this might have happened actually has to do with the election. JFK told the Chicago Mafia that if they got people to vote for him he would leave them alone. This happened, but Bobby Kennedy really pushed to get rid of organized crime (Thomas 14-17). When this started to happen the Mafia was not happy because JFK had made a promise to them. Some say that they were mad at JFK himself, but most thought they were more mad at Bobby Kennedy. They thought that the best way to get back at someone was not to kill them, but to take
