The Times has an article about Kennedy's endorsement of Obama. This line jumped out at me:
Both the Clintons and their allies had pressed Mr. Kennedy for weeks to remain neutral...And all I could think of was the passage from The Prince where Machiavelli explains that if two nearby states are in conflict, the one asking for your armed support is your friend, and the one asking for your neutrality is not.
For some reason, watching the Clintons lately has brought Machiavelli to mind quite often the last few weeks.