Spectator sport doesn't get much better than the first half of the 2008 US presidential election. But there comes a moment in any drama when both actors and audience need a break in the tension.
And we are coming up to my favourite bit: the guessing game about the vice-presidency - the moment when the focus shifts from the protagonists to the comic functionaries. For the porter in Macbeth, read Spiro Agnew or Dan Quayle.
