...the predicted Republican vote share (of the two-party vote) is 48.09 percent. So the prediction is 51.91 for the Democrats and 48.09 for the Republicans, for a spread of 3.82.
The current situation is unusual in that the economy since the end of the third quarter appears to have gotten much worse. People may perceive the economy to be worse than the economic values through the third quarter indicate, which, other things being equal, suggests that the vote equation may overpredict the Republican share.
But only slightly, McCain appears to have gotten 47%