John F. Kennedy assassination conspiracy theories of the plot was thwarted, the authors allege, because it would have revealed embarrassing evidence of American government involvement with organized crime in plots to kill Castro. A 2003 Gallup poll indicated that nearly 20% of Americans suspected Lyndon B. Johnson of being involved in the assassination of Kennedy. Critics of the Warren Commission have accused Johnson of plotting the assassination because he "disliked" the Kennedys and feared that he would be dropped from the Democratic ticket for the 1964 election. According to journalist Max Holland, the first published allegation that Johnson perpetrated the assassination of Kennedy appeared in Penn
John F. Kennedy assassination conspiracy theories no evidence that the Soviet Union was involved in the assassination of President Kennedy. The House Select Committee on Assassinations also wrote: "The committee believes, on the basis of the evidence available to it, that the Soviet Government was not involved in the assassination of President Kennedy". According to some conspiracy theorists, the Soviet Union, with Nikita Khrushchev motivated by having to back down during the Cuban Missile Crisis, was responsible for the assassination. According to a 1966 FBI document, Colonel Boris Ivanov—chief of the KGB Residency in New York City at the time of the assassination—stated that it was