Using the regression methodology of Ray Fair (“The Effect of Economic Events on Votes for President,” The Review of Economics and Statistics, May 1978), I estimate a 46.42% +/- 2.54 McCain share in the Obama-McCain race.
This method doesn’t address social acceptability bias or attempt to estimate the changes in the distribution of voters. I assume the net effect of these factors is zero.
That said, Obama should be the new president.