Which Polls Fared Best (and Worst) in the 2012 Presidential Race by Nate Silver

Among the more prolific polling firms, the most accurate by this measure was TIPP, which conducted a national tracking poll for Investors’ Business Daily. Relative to other national polls, their results seemed to be Democratic-leaning at the time they were published. However, it turned out that most polling firms underestimated Mr. Obama’s performance, so those that had what had seemed to be Democratic-leaning results were often closest to the final outcome.

Rasmussen was Republican-biases as I have always thought.