That's actually an ironic example, seeing how so many (maybe most) viewers took the intended satire at face value, essentially looping all the way back to Heinlein's intent.
The best satire is always convincing to its targets, because it doesn't misrepresent their positions. The Prince may be satire; who knows what was in Machiavelli's head.
Exactly. Even today, a lot of satire aimed at the 'right', viewed from the 'right's perspective is not realized as satire and is viewed like someone is trying to make a real point. They can't tell it is satire.
Doesn't the guy have another book - The Discourses on Livy, that confirms the general gist of The Prince? (i.e. autocracies are horrible, to be a successful autocrat you need to be brutal and ruthless)