You're right. National polls are mostly just informational entertainment. State-by-state polls are more important, especially the early states which tend to affect the rest of the election.
So, let's look at some of the early states, shall we?
Any poll of Iowa is meaningless. They don’t accurately gauge who will go to the caucus on a cold winter’s night. Check the historical record or ask Howard Dean.
Those graphs pretty must depict the trajectory of this upcoming election.
And if you’re Mitt Romney, you’ve got all the encouragement in the world to turn on the jets and finish this thing. He’s put himself in excellent position and run a very effective campaign.