Who cares?
I bet, either way, he wishes he never said it.

I think he was just trying to be clever.
Play off of the Sarah Palin joke from the RNC convention.
I think older folks should also rise up. Was he just referring to McCain's policies or his age? In each case, I think he was trying to kill two birds with one stone. Make a joke of the candidate, while attacking the policy.
You have to be careful when throwing stones. Especially when you live in a glass house(of change).