First Post-Debate Results

President Obama’s loses his lead in national likely-voter polls after the Denver debate.

The five likely-voter polls taken since October 4th suggest the 2012 Election is now tied.  Extrapolating the President’s trend in likely-voter polls taken between July 4th and the October 4th debate would have put him ahead of Mr. Romney by the comfortable margin of six percentage points.  The five polls taken since the debate suggest that lead has been erased.  Even with so few polls, the estimated swing of 6% in Mr. Romney’s favor is highly significant with a value five times its standard error.  The 95% confidence interval for the shift in the President’s support ranges from -9.7% to -3.6%.

The President’s trend in the polls this campaign hardly deviated from his progress in 2008 before the Denver debate.  He picked up support a bit more quickly in 2008 and reached a predicted margin in the polls on Election Day of 7.3%, nearly identical to his actual margin of victory in the popular vote. The slightly slower pace of growth in the President’s support in 2012 put the President on a trajectory to reach 6.0% by November 6th. The estimated -6.0% post-debate swing eliminates all that advantage.