There’s a lot of “back” talk this election

When we say “I’ve got your back,” we’re telling the other person that he (or she) can rely upon us.  We’ll be there to catch them when they fall.  When you turn your back on someone, you are abandoning them, and doing so in a rude and public fashion.  Back metaphors, in other words, bespeak trustworthiness or abandonment.

I’ve noticed that this election campaign involves a lot of references to Obama’s back.  For example, this video talks about the way in which Obama has turned his back on Israel, after first trumpeting that “I have Israel’s back” (h/t NRO’s Corner):

Sandra Fluck’s incoherent convention speech made explicit references to backs too:

The Democratic National Convention bumped Georgetown law student Sandra Fluke up into the 10 p.m. hour, where she received a standing ovation and told delegates they faced a choice between “a country where our president either has our back or turns his back.”

And the Economist did a fairly nasty cover asking about Obama’s plan for the next four years — and showing his back:

I’m sure you can find many more examples, but those three struck me in the last 24 hours. My question for you is this: Why has Obama’s back become such a powerful metaphor for his presidency? Is it really the best short hand for talking about his reliability (or lack of same) and his way of throwing people under the bus?