Agreed, Fredo was passed over because he didn't have a good sense of judgment, if he wasn't the Godfather's son he could have just as easily been killed with Paulie back in the first Godfather. That guy was seriously half retarded or something, he pretends not to know Johnny Ola then makes an announcement to everyone that he learned about that weird nightclub with the girl being tied up from Johnny Ola, then is dumb enough to confess to the senator old man Roth isn't into that thing... and the Senator was an even bigger freak.. some prostitute from one of the brothels ends up all bloody and dead in front of him then a few months later he is laughing and telling jokes in a similar type setting...