Most telling for me was chief strategist, David Axelrod, talking about the difficulties of campaigning against friends in Primaries or internal party elections. Axelrod had worked for Hilary Clinton in her first Senate campaign and now found himself working on the other side.
I had exactly that experience when I worked as Director of Communications for Alan Johnson in the Labour deputy leadership elections. Hilary Benn, another of the six candidates, is an old friend of mine and as a Labour Party staff member I worked as his campaign manger in the Leeds Central by-election where he first won his seat.
XP: Wolfstar blog