Interesting though, that all the way back to FDR, they have always picked the winner except for Truman-Dewey and Carter-Ford.
http://www.gallup.com/poll/9442/election-polls-accuracy-record-presidential-elections.aspx
And from Eisenhower’s re-election in 1956 (excluding Bush in 2004), the incumbent has also received about 2% less in the actual vote than their final poll...so count on Zero to slightly underperform his final poll number...