Are the Polls Right About Obama's Imminent Landslide?
Both the polls and Intrade are predicting that John McCain will suffer a defeat as bad or worse than Bob Dole's in 1996 and George H.W. Bush's in 1992. So, how did the polls do in the 2004 election? The chart below shows that, for this time period in 2004, the polls consistently underestimated George W. Bush.
At this time in 2004, the polls were very close. The highest error in the last eleven days of polling occurred on November 1, 2004 when John Kerry was the projected winner with 298 electoral votes. That prediction underestimated George W. Bush's victory by 55 electoral votes (more than 10% of the total Electoral College.)
The bad news for John McCain is that Intrade and the polls would have to be wrong by over 100 electoral votes in order for him to win. That would be a massive failure of the polls and the Intrade prediction market. The question now is not whether or not Obama will win, but how big the margin of victory will actually be.
polling data and poll-averaging algorithm
are from of Electoral-Vote.com