http://en.wikipedia.org/wiki/Rasmussen_Reports#Elections
"According to Politico, "Rasmussens final poll of the 2008 general election showing Obama defeating Arizona Sen. John McCain 52 percent to 46 percent closely mirrored the elections outcome."[40] In reference to the 2008 presidential election, a Talking Points Memo article said, "Rasmussen's final polls had Obama ahead 52%-46%, which was nearly identical to Obama's final margin of 53%-46%, and made him one of the most accurate pollsters out there."[41] An initial Nov.5, 2008 Fordham University analysis ranked 23 survey research organizations on the accuracy of their final, national pre-election polls, assuming a 6.15% margin of victory by Obama. Rasmussen Reports and Pew Research Center tied as the most accurate.[42] Obama's actual margin was 7.2%, and
a complete analysis published in 2009 by the same author, Costas Panagopoulos, revealed Rasmussen to be tied for 9th most accurate. Democracy Corps, Foxnews/Opinion Dynamic, CNN/Opinion Research, and Ipsos/McClatchy all predicted an accurate seven point spread."