So many well reasoned arguments can be created so it is possible for people's minds to cloud.
I have no idea what you are trying to say here but it seems like it's not contributing anything much to the discussion. Perhaps your mind clouded before you wrote it?
edit: did you edit your original post /after/ I replied?
And think about the number of people involved in an organisation like that who pledged allegiance to serve their country and now have to go along with killing the president. Just so incredibly unlikely. People watch too many cloak and dagger movies.
In that scenario, all you need to do is believe that the interests of the country are separate from the interests of a particular president.
Trump is a classic example where some people might have held that view.
Conjecture: A is not the culprit because motive xyz does not check out.
Reasoning: That doesn't exonerate A, who could have other motives.
Without agreeing with it, that looks perfectly well reasoned to me.
Compelling evidence exonerating the CIA you say? Well ok, I'll believe that when I see it, just like any other evidence from gravity onward. The CIA's docs haven't been declassified and released.