Gerald Posner goes into some of that in his book. It was the left that started the conspiracy theories. They realized they needed to misdirect the country’s attention from the fact that Kennedy was killed by a leftist. So they turned on the smoke machines full blast and 50 years later the confusion remains.
Yup, and the KGB supported the conspiracy nonsense to undermine faith in the American government. Combine that with the big bad “McCarthyites” from the 1950s and the right has been labeled as fascists ever since.
Richard Russell was no leftist, and he publicly doubted that Oswald acted alone. Your hero Earl Warren , in contrast, was a leftist