It's pretty obvious to rational people; the problem is, so few people are. I've read all the conspiracy books as well, and they just don't hold up. You get people who say (just for example), "How do you explain Oswald's trip to Mexico City, then, huh?" and the answer from a person who understands evidence is: "I don't explain it. I don't have to explain it. If you have a theory about Oswald's trip to Mexico City, put it out there, elaborate on how it makes everything work and get some other solid facts behind it." Introducing huge numbers of disconnected tidbits isn't a challenge to a real theory of the crime.
My wife just got me Bugliosi's book, but I'm so far behind I've got literally stacks of things in the queue to read. If you close it out before I do drop me a FReepmail and let me know if it's worth the time. I didn't care much for his treatment of the Clinton Impeachment, but his book on the OJ Simpson murder trial was both a spectacular rant and a penetrating analysis. I've recommended it to many. My favorite passage concerns Judge Ito: "What do you call a lawyer with an IQ of 75? Your Honor."