In 1992, fewer than one-third of Americans accepted the Warren Commission’s conclusions as persuasive… The fact that none of the conspiracy theorists have been able to offer convincing evidence of their suspicions does not seem  to trouble many people. The plausibility of a conspiracy is less important to them  than the implausibility of someone as inconsequential as Oswald having the wherewithal to kill someone as consequential — as powerful and well guarded — as Kennedy. To accept that an act of random violence by an obscure malcontent could bring down a president of the United States is to acknowledge a chaotic, disorderly world that frightens most Americans.  Believing that Oswald killed Kennedy is to concede, as New York Times columnist Anthony Lewis said, “that in this life there is often tragedy without reason.”

Robert Dallek, “John F. Kennedy: An Unfinished Life, 1917-1963”.