If Indiana is tied, then Obama will win the state, because McCain has absolutely no organization there. No campaign offices. No GOTV structure. No ads. If Indiana is tied or even McCain +2 or so come election day, Obama's organization will win it.
Or maybe it IS tied because of Obama's organization.
Well, to a degree, yes. But polls don't pick up GOTV organization; they can't. I'd also think that Obama's supporters, after being actively campaigned for for months are more enthusiastic and excited about voting than the essentially ignored McCain supporters, which again won't completely manifest itself in the polls.
