Presidential polling more than a year out from an election tends to be very unreliable. When people post polls saying that Obama leads Romney by whatever amount, I usually dont take them very seriously.
The reason is that polling often changes in the lead up to an election due to conventions and other events.
For instance, this April 1995 poll(http://www.fandm.edu/...) gave Bob Dole a 45%-41% lead over President Bill Clinton in the state of Pennsylvania. A year and half later, Clinton easily won the state.
Up until July 1992, most polls showed President Bush leading Bill Clinton and by wide margins. One May 1992 poll had Bush up 47%-31% over Clinton in the state of Colorado, which Clinton ended up winning easily in November. http://articles.latimes.com/...
The point is that early polls mean very little. Sure, they are fun to look it and talk about, but they really mean nothing until the conventions are over.