I didn't suspect LBJ was behind the assassination until I read McClellan's book. I wouldn't say that book proves its case, but I did find it highly persuasive. (I was perhaps unusually receptive to McClellan's case because I recently read the latest volume of Caro's life of LBJ, which makes me believe LBJ was capable of this sort of crime. Caaro is a liberal, and so he is, in my opinion, too kind to the man, but he does not disguise the man's faults.)
So I think something like McClellan's book is capable of changing people's minds.
I didn't suspect Johnson either. What persuades me is his relationship with convicted murderer Mac Wallace. There is no doubt as to that relationship. And the murder of Marshall and it's coverup has LBJ written all over it since Wallace was investigating LBJ. Then, lo and behold, there's Mac Mallace's print in the sniper's nest.
So I think something like McClellan's book is capable of changing people's minds.
Yeah, hopefully more and more will come forward as they feel safer.