Spare Change because he was who the Democrats had left over after the uber-primary season. Spare in that he doesn't really have any real "change" for us - just warmed over socialism. He can give a prepared speech like no other but has no experience. He does not have any special skills or magical powers. Spare in his ability to keep America safe. Spare in his military experience. Spare in his economic plan because he keeps using the failed plans and words of the past, as well as crooked economic advisors. Obama is Jimmy Carter "Lite". Our enemies know it, too. No wonder they root for him!
Loose Change because he can become unhinged.
We'll see it in the debate with Palin... his eyes will start to twitch and he'll say something outrageous. Joe Biden is "change"? He's been witnessed making things up, being rude to members of his own party. (which he actually has in common with McCain) His childish prattle causes even young senators to fall asleep in meetings. Biden's been called by other Democrats a "Loose Cannon" - Hence the concept "loose change." It's change you get, but not the type you want. Think Monty Python.
Is it the fact that they just have very similar biological features or is there some truth in the folk wisdom that physical appearances are merely manifestations of the soul.
If you are seen as accustomed to trying to bilk people out of their money for your own personal gain, and you are commonly known as a "confidence man", is that the kind of change we need from a VP candidate?