Because power corrupts, society's demands for moral authority and character increase as the importance of the position increases.
Culture means, I think, that you have widened your experience enough through reading and through being a little bit thoughtful about these things that it has changed your outlook in some ways. And not necessarily made you a better human being but made you see things.
I'm not tempted to write a song about George W. Bush. I couldn't figure out what sort of song I would write. That's the problem: I don't want to satirise George Bush and his puppeteers, I want to vaporise them.