I think any poll taken before the first debate is crap.
For the most part, I agree. But when the butt rashes like Salt Peter and his liberal Democrat brothers and sisters constantly "assure" all the rest of us that the "race" is already effectively "over," I think the current mood (as reflected with some accuracy) in a present day poll MIGHT be instructive.
2012 Presidential Election Interactive Map and History of the Electoral College
CLick on NC on the interactive map of present day electoral count (a map that presupposes the races state by state come out as indicated): When it turns RED, the race has tightened up NICELY.
And FLA is always dicey, but the President happens to suck dick at his job. SO if FLA goes red, too, (try it) the race is no longer such a ******* "gimmee" for the incumbent.